Pixco Pro Lens Adapter for M42 Lens to Canon EOS Mount Digital Camera Adapter Ring 50D 500D 5D Mark II 70D 60D 450D 400D This adapter allows user to use M42 mount lenses (Zeiss, Pentax, Praktica, Mamiya, Zenit) on Canon EOS cameras For Canon 1D 1Ds 5D Mark II III 6D 7D 70D 60D 50D 40D 30D 700D 650D 600D 550D 500D 450D 1100D 1000D Rebel Series DSLR and new models Compatible with:Canon EOS 760D, 750D, 5DS(R), 5D Mark III, 5D Mark II, 1Ds Mark [IV / III / II / I ], 1D Mark [III / II N/ II / I], 6D, 5D, 7D, 70D, 60D, 50D, 40D, 30D, 100D, 700D, 650D, 600D, 550D, 500D, 450D, 400D, 350D, 300D, 1200D, 1100D, 1030D To Mount: Mount the Lens onto the adapter then mount them onto the camera. Put red marks of the adapter and lens collar together. Turn the adapter clockwise till the fixative click. To Remove: Remove both lens / adapter together from the camera, press the lens lock and then remove the adapter from the lens simultaneously.