Compatible lenses: Pentax K mount Compatible cameras: Canon EF mount * Cannot be used with full-frame cameras with large mirrors, as the lens may come into contact with the camera's mirror. [Removal Procedure] I remember the procedure being as follows, but there may be some discrepancies: 1. Remove the lens from the body while the adapter is still attached. 2. Press the leaf spring-like part on the adapter to release the lock. 3. Rotate the adapter while maintaining the unlocked state. I don't use it anymore, but I used it for about a year, so there is a feeling of use on the mount's fastening parts, etc.