• Standard and Stress-Free Retaining Rings
• Retaining Rings for our Ø0.5", Ø1", Ø2", and Ø3" Lens Tubes and Mounts
• Ø18 mm, Ø30 mm, Ø1.5", and Ø75 mm Rings for Our Lens Mounts

Thorlabs offers a wide selection of retaining rings for securing optical components into our threaded mounts and lens tubes. Available in both standard and stress-free designs, the standard retaining rings are compatible with Ø0.5", Ø1", Ø1.5", Ø2", Ø3", Ø18 mm, Ø30 mm, and Ø75 mm mounts, while the stress-free versions are fabricated for use with Ø0.5", Ø1", and Ø2" mounts; both designs enable mounting of standard size optics. The stress-free versions (SM05LTRR, SM1LTRR, and SM2LTRR) have a rubber O-ring that provides a light-tight seal around the optical components; then, two retaining rings can be used to secure the optical component inside the center of a lens tube, one as a stopper and the other to lock in the component.

Thorlabs also offers a line of compatible spanner wrenches, including fixed diameter wrenches as well as adjustable spanner wrenches for any rings with diameters ranging from 1/4" to 3". The spanner wrench holes on the SM3RR have been changed to slots.