Ø1/2" Lens Tubes

Directly Accepts Ø1/2" (12.7 mm) Optics
Compatible with Our 16 mm Cage Systems
Stackable Design is Compatible with SM05-Threaded Components

SM05L30C

Slotted Lens Tube

SM05M10

Lens Tube Without External Threads

SM05L03

Lens Tube with Internal and External Threads

SM05RR

Retaining Ring

SPW603

Spanner Wrench

SM05

SM1

SM2

SM3

Easily Interfaces with Other Lens
Tube Sizes

SM05L03V

Lens Tube with Internal and External Threads

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Overview
Threading Specs
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Ø1/2" Shortcuts
Lens Tube Couplers SM Thread Adapters Lens Tube Mounts End Caps Kinematic Mounts Fixed Lens Mounts Rotational Mounts Translation Mounts

Additional Lens Tube Sizes
Ø1" Ø30 mm Ø1.5" Ø2" Ø3"

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When an engraved lens tube is attached to another lens tube, the engraving of the connected end is no longer visible.

Features

Easily Construct Multi-Element Optical Systems
Wide Range of SM05-Compatible Options Available
Directly Accepts Ø1/2" (Ø12.7 mm) Optics
Compatible with Our 16 mm Cage Systems
Available With or Without External SM05 Threads
Vacuum-Compatible Options Available
Can be Used with Ø5 - Ø9 mm Optics by Purchasing a Small Optic Adapter

Lens tubes are ideal for creating compact optical subassemblies. The Ø1/2" lens tubes sold here can be used to house one or several optical elements, as shown in the diagram of a beam expander below. Optics are separated and secured by retaining rings that are positioned at the desired depth within the lens tube using our SPW603 or SPW603L spanner wrenches. Depending on the item purchased, one or two retaining rings are included (see below for details). Additional retaining rings can be purchased separately. In addition to the Ø1/2" lens tubes featured on this page, Thorlabs also offers Ø1", Ø30 mm, Ø1.5", Ø2", and Ø3" versions, each of which is equipped with an SM series thread standard that depends on the tube diameter. Vacuum-compatible versions of our Ø1/2" and Ø1" stackable lens tubes are available from stock; customers can request vacuum-compatible lens tubes at other lengths and diameters by contacting Tech Support.

Lens Tube Compatible Products
Thread Adapters	Terminated Fiber Adapters	Fixed Fiber Collimator Adapters	Kinematic Fiber Collimator Adapters	LED Mounts	LD Mounts	Aspheric Lens Mounts	Irises, Apertures, and Shutters	Alignment Tools

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Threading Specifications

The following is a general overview of screw threading. For more details regarding specifications and dimensions, please consult the Machinery's Handbook, available for purchase at many bookstores.

Features of a Thread
A thread consists of three repeating features: a crest, flank, and root (see drawing to the right). Except in special cases, threads have symmetrical sides inclined at equal angles when a vertical line is drawn through the center of a crest or root. The distance between corresponding points on adjacent threads is known as the pitch of the thread. The flank angle is defined as the angle the flank makes with a perpendicular ray drawn from the screw axis. Unless otherwise stated, threads have a flank angle of 30°, resulting in a total angle between flanks of 60°. Each feature is shown in the diagram to the right.

The major diameter is taken from the crests of a thread while the minor diameter is taken from the roots. For most screws, crests and roots do not terminate at a sharp point, so crest and root truncation values are included in the definitions of major and minor diameter. The pitch diameter is approximately halfway between the major and minor diameters.

Thread Form
A thread form is a set of rules that define the features' scale relative to one another. Common thread forms include the Unified Screw Thread Form, used in the United States of America and measured in imperial units, and the ISO Metric Screw Thread Form, used in many parts of the world and measured with the International System of Units. There are many thread forms in the Unified screw thread standard designated by either UN, which defines a flat root contour, or UNR, which defines a round root contour. These can be further described by appending more letters. For example, an extremely fine thread with a flat root contour is designated UNEF. Those forms which are not standardized by the Unified screw thread system are designated UNS.

Thread Series
Most screws are identified by their thread series. Thread series are denoted by the major diameter and density of threads. Unified threads specify density in threads per inch, while Metric threads specify the thread pitch. For example, in the Unified nomenclature, a 1/4"-20 cap screw has a 1/4" diameter barrel and the pitch is 20 threads per inch (TPI). In metric nomenclature, an M4 x 0.7 cap screw has a 4 mm barrel and the pitch is 1 thread per 0.7 mm. The term M4 x 0.7 is often shortened to just M4.

Unified Thread Class Tolerancing
Location	Loose	Optimal	Strict
Internal	1B	2B	3B
External	1A	2A	3A

Metric Thread Tolerance Positions
Location	Loose	Optimal	Strict
Internal	-	G	H
External	e or f	g	h

Metric Thread Tolerance Grades
Dimension	Location	Tolerance Grades^a
Minor Diameter	Internal	4, 5, 6, 7, 8
Major Diameter	External	4, 6, 8
Pitch Diameter	Internal	4, 5, 6, 7, 8
Pitch Diameter	External	3, 4, 5, 6, 7, 8, 9

The tolerance becomes looser as the grade increases. The underlined grades are used with normal lengths of thread engagement.

Thread Class
The tolerances and allowances on a thread series are given by a thread class. Unified thread classes are alphanumeric identifiers starting with a number from 1 through 3, where 1 is the loosest tolerance and 3 is the tightest, and either A for external threading or B for internal threading.

Metric threads have a slightly more complex tolerancing method that uses tolerancing grades, designated by a number 3 through 9; and tolerancing positions, which use letters e through h. Grades provide a measure of the tolerance itself: the smaller the number, the tighter the tolerance. Positions denote the distance of the tolerance from the pitch diameter. Uppercase positioning letters indicate internal threads while lowercase positioning letters indicate external threads.

Quoting from the Machinery's Handbook, 29th Edition, p. 1885: "To designate the tolerance class, the grade and position of the pitch diameter is shown first followed by that for the major diameter in the case of the external thread or that for the minor diameter in the case of the internal thread, thus 4g6g for an external thread and 5H6H for an internal thread. If the two grades and positions are identical, it is not necessary to repeat the symbols, thus 4g, alone, stands for 4g4g and 5H, alone, stands for 5H5H."

Thorlabs' SM Series Threads
Threading specifications for our SM threads, utilized in our lens tube and cage system components, are given below so that you can machine mating components to suit your application. Most SM series threads utilize a non-standard Unified thread form, indicated by the letters UNS, with a 30° flank angle and a thread class of 2A and 2B. The exception is our SM30 series thread, which is a Metric thread form with a 30° flank angle and a tolerance of 6H/6g. We also offer products with C-Mount and RMS threads, and the specifications for these threads are given below for reference. Please note that other manufacturers may have different tolerances for C-Mount and RMS threads. For other thread specifications that are not listed here, please contact Tech Support.

SM05 Threading: Ø1/2" Lens Tubes, 16 mm Cage Systems
External Thread, 0.535"-40.0 UNS-2A		Internal Thread, 0.535"-40.0 UNS-2B
Max Major Diameter	0.5340"	Min Major Diameter	0.5350"
Min Major Diameter	0.5289"	Min Pitch Diameter	0.5188"
Max Pitch Diameter	0.5178"	Max Pitch Diameter	0.5230"
Min Pitch Diameter	0.5146"	Min Minor Diameter (and 83.3% of Thread)	0.508"
Max Minor Diameter	0.5069"	Max Minor Diameter (and 64.9% of Thread)	0.514"

RMS Threading: Objective, Scan, and Tube Lenses
External Thread, 0.800"-36.0 UNS-2A		Internal Thread, 0.800"-36.0 UNS-2B
Max Major Diameter	0.7989"	Min Major Diameter	0.8000"
Min Major Diameter	0.7934"	Min Pitch Diameter	0.7820"
Max Pitch Diameter	0.7809"	Max Pitch Diameter	0.7866"
Min Pitch Diameter	0.7774"	Min Minor Diameter (and 83.3% of Thread)	0.770"
Max Minor Diameter	0.7688"	Max Minor Diameter (and 64.9% of Thread)	0.777"

C-Mount Threading: Machine Vision Lenses, CCD/CMOS Cameras
External Thread, 1.000"-32.0 UN-2A		Internal Thread, 1.000"-32.0 UN-2B
Max Major Diameter	0.9989"	Min Major Diameter	1.0000"
Min Major Diameter	0.9929"	Min Pitch Diameter	0.9797"
Max Pitch Diameter	0.9786"	Max Pitch Diameter	0.9846"
Min Pitch Diameter	0.9748"	Min Minor Diameter (and 83.3% of Thread)	0.966"
Max Minor Diameter	0.9651"	Max Minor Diameter (and 64.9% of Thread)	0.974"

SM1 Threading: Ø1" Lens Tubes, 30 mm Cage Systems
External Thread, 1.035"-40.0 UNS-2A		Internal Thread, 1.035"-40.0 UNS-2B
Max Major Diameter	1.0339"	Min Major Diameter	1.0350"
Min Major Diameter	1.0288"	Min Pitch Diameter	1.0188"
Max Pitch Diameter	1.0177"	Max Pitch Diameter	1.0234"
Min Pitch Diameter	1.0142"	Min Minor Diameter (and 83.3% of Thread)	1.008"
Max Minor Diameter	1.0068"	Max Minor Diameter (and 64.9% of Thread)	1.014"

SM30 Threading: Ø30 mm Lens Tubes
External Thread, M30.5 x 0.5 – 6H/6g		Internal Thread, M30.5 x 0.5 – 6H/6g
Max Major Diameter	30.480 mm	Min Major Diameter	30.500 mm
Min Major Diameter	30.371 mm	Min Pitch Diameter	30.175 mm
Max Pitch Diameter	30.155 mm	Max Pitch Diameter	30.302 mm
Min Pitch Diameter	30.059 mm	Min Minor Diameter (and 83.3% of Thread)	29.959 mm
Max Minor Diameter	29.938 mm	Max Minor Diameter (and 64.9% of Thread)	30.094 mm

SM1.5 Threading: Ø1.5" Lens Tubes
External Thread, 1.535"-40 UNS-2A		Internal Thread, 1.535"-40 UNS-2B
Max Major Diameter	1.5339"	Min Major Diameter	1.535"
Min Major Diameter	1.5288"	Min Pitch Diameter	1.5188"
Max Pitch Diameter	1.5177"	Max Pitch Diameter	1.5236"
Min Pitch Diameter	1.5140"	Min Minor Diameter (and 83.3% of Thread)	1.508"
Max Minor Diameter	1.5068"	Max Minor Diameter (and 64.9% of Thread)	1.514"

SM2 Threading: Ø2" Lens Tubes, 60 mm Cage Systems
External Thread, 2.035"-40.0 UNS-2A		Internal Thread, 2.035"-40.0 UNS-2B
Max Major Diameter	2.0338"	Min Major Diameter	2.0350"
Min Major Diameter	2.0287"	Min Pitch Diameter	2.0188"
Max Pitch Diameter	2.0176"	Max Pitch Diameter	2.0239"
Min Pitch Diameter	2.0137"	Min Minor Diameter (and 83.3% of Thread)	2.008"
Max Minor Diameter	2.0067"	Max Minor Diameter (and 64.9% of Thread)	2.014"

SM3 Threading: Ø3" Lens Tubes
External Thread, 3.035"-40.0 UNS-2A		Internal Thread, 3.035"-40.0 UNS-2B
Max Major Diameter	3.0337"	Min Major Diameter	3.0350"
Min Major Diameter	3.0286"	Min Pitch Diameter	3.0188"
Max Pitch Diameter	3.0175"	Max Pitch Diameter	3.0242"
Min Pitch Diameter	3.0133"	Min Minor Diameter (and 83.3% of Thread)	3.008"
Max Minor Diameter	3.0066"	Max Minor Diameter (and 64.9% of Thread)	3.014"

SM4 Threading: Ø4" Lens Tubes
External Thread, 4.035"-40 UNS-2A		Internal Thread, 4.035"-40.0 UNS-2B
Max Major Diameter	4.0337"	Min Major Diameter	4.0350"
Min Major Diameter	4.0286"	Min Pitch Diameter	4.0188"
Max Pitch Diameter	4.0175"	Max Pitch Diameter	4.0245"
Min Pitch Diameter	4.0131"	Min Minor Diameter (and 83.3% of Thread)	4.008"
Max Minor Diameter	4.0066"	Max Minor Diameter (and 64.9% of Thread)	4.014"

Posted Comments:

Su Beom Heo (posted 2023-07-05 10:53:40.36)

Hi I wonder if there is tube for C-MOUNT Camera connection.

jdelia (posted 2023-07-05 12:59:27.0)

Thank you for contacting Thorlabs. Our C-mount extension tubes can be found here: https://www.thorlabs.com/navigation.cfm?guide_id=2416. We have also reached out to you directly to discuss your application further.

user (posted 2021-05-20 16:47:37.037)

Is this lens tube also made from 6061-T6 Aluminum like SM1V10V? Can I know the exact material of SM05L30?

YLohia (posted 2021-05-21 10:54:54.0)

The SM05L30 is also made of 6061-T6 Aluminum, but is black anodized.

Peter VOKHMIN (posted 2020-04-30 15:43:19.847)

Hi guys: It is desirable to see in the ThorLabs Catalogue Ø1/2" lens tubes without external SM05 threads, but with the optic retention lips, similar to the Ø1" lens tubes SM1L10E or SM1L05E. Best wishes. Dr. P.A.Vokhmin

YLohia (posted 2020-05-01 03:19:38.0)

Hello Peter, thank you for your suggestion. I have posted your request to our internal engineering forum for further consideration as a future product.

swaush (posted 2017-04-27 17:22:53.673)

Hello Could you let us know the manufacturing tolerance of the lens tubes without external threads, 1.5 and 2 inch length? We would need the tolerance of the length and outer diameter.

nbayconich (posted 2017-04-28 11:06:16.0)

Thank you for contacting Thorlabs. A Techsupport representative will contact you directly regarding our mechanical tolerances.

s13d504 (posted 2013-05-30 22:34:59.403)

Hello,this is Wei Qi,from Kagawa Unv. Japan. We want to buy SM05L05,but we don't know that the lens(Diameter:12.7mm or smaller)can be used in the lens tubes? If the lens(Diameter:12.7mm or smaller)can be used in this lens tubes, the other parts is necessary? You can contact me by e-mail s13d504@stmail.eng.kagawa-u.ac.jp Thank you very much. Regards,

tcohen (posted 2013-05-30 12:39:00.0)

Response from Tim at Thorlabs to Wei: The retention lip is .450” and lenses with a diameter larger than that will be restricted. A 12.7mm lens will pass through the SM05 threads to the retention lip and be held in with a retaining ring (included). Smaller optics can be adapted to the SM05 standard with adapters such as our LMRA series: http://www.thorlabs.com/NewGroupPage9.cfm?ObjectGroup_ID=59.

jlow (posted 2012-07-31 12:19:00.0)

A response from Jeremy at Thorlabs. Thank you for your feedback. I have forwarded your feedback to our engineering group to be added. The inner diameter for the part you referenced is Ø0.450".

user (posted 2012-07-31 09:36:49.0)

The dimension of the ID of the externally threaded end is missing from the SM05L05 lens tube drawing. As this diameter defines the maximum aperture of the back end of the lens tube i would consdier it an important number to provide. Please be kind enough to add this dimension.

jjurado (posted 2011-02-15 08:39:00.0)

Response from Javier at Thorlabs to sivan.jonathan: Thank you very much for submitting your request. I will send you the specs for our SM05 threads to your e-mail. We will also post this information on the web shortly.

sivan.jonathan (posted 2011-02-14 13:36:51.0)

Hello, I need to interface with this product, both to external and internal threading. Can I recieve the engineering specs for these threads (they are not standard). Specifically tap, diameters etc...

Ø1/2" Stackable Lens Tubes

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Stackable Design Enables Multi-Element Optical Systems
SM05-Threaded (0.535"-40) Bore Directly Accepts Ø1/2" (12.7 mm) Optics
Accommodates Ø5 - Ø9 mm Optics by Purchasing a Small Optic Adapter
Directly Compatible with Our 16 mm Cage Assembly Systems

Item #	L	Internal Thread Depth
SM05L03	0.33" (8.4 mm)	0.30" (7.6 mm)
SM05L05	0.53" (13.5 mm)	0.50" (12.7 mm)
SM05L10	1.03" (26.2 mm)	1.00" (25.4 mm)
SM05L15	1.53" (38.9 mm)	1.50" (38.1 mm)
SM05L20	2.03" (51.6 mm)	2.00" (50.8 mm)
SM05L30	3.03" (77.0 mm)	3.00" (76.2 mm)

Alternatives	Ø1", Ø30 mm, Ø1.5", Ø2", and Ø3" Stackable Lens Tubes	Ø1" and Ø2" Lens Tube Extensions

Vacuum-Compatible Ø1/2" Stackable Lens Tubes

Vacuum-Compatible Ø1/2in Stackable Lens Tubes

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Click to Enlarge
Vents along the threading and at the ends of these tubes provide a free path for air to escape when under vacuum.

Stackable Design Enables Multi-Element Optical Systems
SM05-Threaded (0.535"-40) Bore Directly Accepts Ø1/2" (12.7 mm) Optics
Compatible with SM05-Threaded Vacuum Components

These stackable Ø1/2" lens tubes provide a fast and easy means for building compact optical assemblies. Their stackable design and direct interfacing with any SM05-threaded (0.535"-40) components provide flexibility for complex optomechanical assemblies. Made from 6061-T6 aluminum, these lens tubes are vacuum compatible down to 10^-6 Torr. One vacuum-compatible SM05-threaded retaining ring is included with each lens tube. Please contact Tech Support for replacements.

These vacuum-compatible lens tubes feature venting channels along the internal threading and at the ends of each tube. These channels allow air trapped between mounted optics an easy means of escape during pumpdown.

Item #	L	Internal Thread Depth
SM05L03V	0.33" (8.4 mm)	0.30" (7.6 mm)
SM05L05V	0.53" (13.5 mm)	0.50" (12.7 mm)
SM05L10V	1.03" (26.2 mm)	1.00" (25.4 mm)

Vacuum Specifications
Vacuum Compatibility as Packaged^a	>10^-6 Torr
Materials	6061-T6 Aluminum
Preparation and Packaging	Chemically Cleaned and Double Vacuum-Bagged

This is the pressure at which these components can be used with no additional processing. They can be used at even lower pressures with additional cleaning and processing.

Alternatives	Ø1" Vacuum-Compatible Stackable Lens Tubes

Ø1/2" Lens Tubes Without External Threads

Ø1/2in Lens Tubes Without External Threads

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SM05-Threaded (0.535"-40) Bore Directly Accepts Ø1/2" (12.7 mm) Optics
Accommodates Ø5 - Ø9 mm Optics by Purchasing a Small Optic Adapter
Unlike Stackable Lens Tubes, Optics can be Accessed from Both Ends
Use Lens Tube Couplers to Stack Multiple Lens Tubes
Allows Coupling of Two Externally SM05-Threaded Components

Unlike our Ø1/2" stackable lens tubes featured above, these internally threaded lens tubes do not feature a lip at one end nor do they have external SM05 threading. Therefore, optics housed inside can be accessed from both ends. To join these lens tubes end-to-end, use an SM05T2 Lens Tube Coupler. Two SM05RR Retaining Rings are included with each lens tube.

Alternatives	Ø1" and Ø2" Lens Tubes Without External Threads

Based on your currency / country selection, your order will ship from Newton, New Jersey

+1 Qty Docs Part Number - Universal Price Available

SM05M05 Customer Inspired! SM05 Lens Tube Without External Threads, 1/2" Long, Two Retaining Rings Included

$17.22

3-5 Days

SM05M10 Customer Inspired! SM05 Lens Tube Without External Threads, 1" Long, Two Retaining Rings Included

$18.84

3-5 Days

SM05M15 SM05 Lens Tube Without External Threads, 1.5" Long, Two Retaining Rings Included

$19.84

3-5 Days

SM05M20 Customer Inspired! SM05 Lens Tube Without External Threads, 2" Long, Two Retaining Rings Included

$21.07

3-5 Days

SM05M25 SM05 Lens Tube Without External Threads, 2.5" Long, Two Retaining Rings Included

$21.73

3-5 Days

SM05M30 Customer Inspired! SM05 Lens Tube Without External Threads, 3" Long, Two Retaining Rings Included

$22.95

3-5 Days

Ø1/2" Slotted Lens Tubes

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The dust cover can be opened or closed by rotating it in either direction.

Easy Access to Optics
Rotatable Slip Shield Protects Optics
Compatible with SM05 (0.535"-40) Threaded Components
Available in 2" (50.8 mm) and 3" (76.2 mm) Thread Depths

These stackable Ø1/2" lens tubes with side slots provide a fast and easy means for building complex optical assemblies and adjusting the optics without disassembling the setup. Optics can be inserted into the tube and locked into position using the included SM05RR retaining rings. Simply thread the first retaining ring to the desired depth, add the optic, and then use a second retaining ring to secure the optic. Optics can be manually adjusted via the side slots without the use of a spanner wrench. The rotatable slip shield included with the lens tube has an inner diameter of 0.71" (17.9 mm) and fits over the lens tube slots to prevent unwanted light from entering the system and to keep the optical setup free from debris.

Alternatives	Ø1" and Ø2" Slotted Lens Tubes

Ø1/2" Retaining Rings and Spanner Wrenches

Ø1/2in Retaining Rings and Spanner Wrenches

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Retaining Ring Specs
Item #	Material	Feature	Thickness	Inner Diameter
SM05RR	Black Anodized Aluminum	Standard	0.07" (1.7 mm)	0.44" (11.0 mm)
SM05RRV	Unanodized Aluminum	Vacuum Compatible^a	0.07" (1.7 mm)	0.44" (11.0 mm)
SM05LTRR	Black Anodized Aluminum	Rubber O-Ring for Stress-Free Mounting	0.15" (3.9 mm)	0.32" (8.1 mm)
SM05RRC	Black Anodized Aluminum	5 mm Thick for High-Curvature Lenses	0.20" (5.0 mm)	0.44" (11.0 mm)
SM05PRR	Plastic	Non-Marring	0.08" (2.0 mm)	0.44" (11.0 mm)
POLARIS-SM05RR	Stainless Steel	Vacuum Compatible^b	0.07" (1.7 mm)	0.43" (10.9 mm)

>10^-6 Torr Vacuum Compatibility as Packaged; Lower Pressures with Additional Cleaning and Processing
>10^-5 Torr at 25 °C Vacuum Compatibility as Packaged without Bake Out; >10^-9 Torr at 25 °C with Proper Bake Out

Six Types of Retaining Rings for Securing Ø1/2" Optics
SPW603 Hollow Spanner Wrench Providing Unobstructed Beam Path During Adjustment
SPW801 Adjustable Spanner Wrench Accommodates Diameters from 0.12" (3.0 mm) to 2.89" (73.4 mm)

The SM05RR is our standard anodized aluminum retaining ring that ships with our Ø1/2" lens tubes as well as many other Thorlabs components and is available individually and in packs of 10. We offer six different SM05-threaded (0.535"-40) retaining rings, shown in the table to the right, which have unique features and can replace an SM05RR retaining ring. Please keep in mind that due to the increased thickness of some retaining rings, the maximum optic thickness that can be housed inside our standard SM05-compatible mounts will be diminished in some cases.

Spanner Wrenches
We offer three spanner wrench choices that can be used with these retaining rings. The SPW603 and SPW603L Spanner Wrenches have a hollow design that enables retaining rings for our SM05 series of lens tubes to be adjusted and installed without obscuring the beam path. For use with longer lens tubes, multiple SPW603 spanning wrenches can be stacked to extend the wrench's maximum reach. Alternatively, the SPW801 Adjustable Spanner Wrench can also be used to position SM05-threaded retaining rings. Please note that the SPW801 wrench can withstand a maximum torque of 80 inch-pounds. We also offer the SPB05 Spanner Bit, which can be used with a standard 1/4" hex driver (sold separately). The SPB05 is included as part of the SPB600 Spanner Wrench Bit Kit.