Allows any M42 lens to be used with full range focus to infinity. The basic adaptor requires auto lenses to have an auto/manual (A/M) switch to allow the lens to be used manually.
Fitting note: Mount the adaptor to the camera body before fitting the M42 lens. If you fit the lens to the adaptor first, the adaptor may not engage with the body correctly due to the positioning of an internal actuator.
