Features M42 to all For Pentax PK mount adapter ring Make M42 mount lenses For Zeiss For Pentax For Praktica For Mamiya For Zenit can be used on For Pentax PKcamerasThere is no ROM connection on the ring so diaphragm control of the lens is set manually It is possible to use Macro rings and other accessories It is able to peform focus to infinite Disassembly instructions Press the trivial reed next to the ring with your thumbnail first Dont let it go The red dot of the connecting ring is aligned with the red dot of the fuselage chuck and the connecting ring is put into the fuselage chuck Continue to hold the reed with your thumbnail Do not let it go Rotate the ring clockwise Turn to be unable to rotate release the reed lock the collar on the fuselage then turn the lens on the collar and start shooting When disassembling first press the locking reed with the thumbnail to unlock it Rotate the ring counter clockwise until it cannot be rotated Take out the connecting ring Package Included 1 xM42 PK Lens Adapter 1 x Removal Tool