A rear cap for your mount, to print yourself.

Choose your mount (Canon EF or RF, Sony E, Nikon Z, L-Mount, Micro Four Thirds, Leica M or ARRI PL), a gear or flute grip and, if you like, your focal length on the face or a hidden AirTag pocket. The cap prints face down without supports, and a free test ring checks the bayonet first.

What you set

Mount: Canon EF / EF-S, Canon RF, Sony E / FE, Nikon Z, L-Mount, Micro Four Thirds, Leica M or ARRI PL; standard or deep rear room for E, Z, L, MFT, M and PL
Grip: module 0.8 gear teeth or rounded flutes
Focal length, your logo or the mount code, as a flush two-colour inlay or engraved for one filament; snap-in AirTag pocket

What you get

Plain EF cap: free 3MF and STL
Other mounts, focal length or AirTag: 3MF, aligned STLs, a fit test ring and a printing guide
Free fit test ring for every mount

New to measuring? Read how to measure a lens for a focus gear.

More generators

Focus ring: A slim slip-on gear for any lens from 40 to 110 mm.
Clamp ring: Three flexure clamps and M4 set screws hold it in place.
Hard-stop ring: Two calibration stops for your lens and focus motor.
Lens cap: A slip-on front cap, smooth or with a gear or flute grip, blank or with your lettering and logo.
Rear lens cap: A twist-on rear cap for EF, RF, E, Z, L, MFT, M and PL, with focal length or an AirTag pocket.
Body cap: A camera body cap for EF, E, L, MFT and PL that clicks in like a lens, with your label or an AirTag pocket.
Lens library: focus gear sizes by lens
Rear lens caps by mount: Canon EF and RF, Sony E, Nikon Z, L-Mount, Micro Four Thirds, Leica M and ARRI PL, with or without AirTag
Journal: guides for measuring and printing
About Focus Rings

The interactive generators need JavaScript. Every file is generated from your dimensions in millimetres, with module 0.8 teeth and engraved sizes.