M12 lens focus adjuster and IR Cut filter holder

thingiverse

The "M12 lens focus adjuster and IR Cut filter holder" is the perfect accessory if you've ripped the original lens out of your Yi 4K, Yi 4K+, older GoPro, or other action camera. It can attach to an M12 mount lens (also known as an S-mount) to allow for easier focus adjustment. It also has space to add an IR Cut filter in front of the lens, for those M12 mount lenses that don't include one. Snaps on tightly to the front of the lens, so does require a bit of force. The slot notched in the side is meant to allow you to line this up with the information on the lens so you can still have a look at what the focal distance of the lens is.