Universal M42 Screw Mount Lens Adapter Ring for Pentax K PK Camera K10D K20D K100D K200D Universal M42 Screw Mount Lens Adapter Ring for Pentax K PK Camera K10D K20D K100D K200D Features: M42 to all Pentax PK mount adapter ring Enables use of M42 mount lenses (Zeiss, Pentax, Praktica, Mamiya, Zenit) on Pentax PK cameras No ROM connection on the ring; diaphragm control of the lens must be set manually Compatible with macro rings and other accessories Material: Brass Note: Although the lens will fit physically, automatic diaphragm, auto-focusing, and other electronic functions will not operate when using this adapter Stop-down metering mode must be used since the camera body cannot control the lens aperture Shooting is possible in manual mode or aperture priority mode (A/V) Compatible With: Lens: M42 mount Camera: Pentax PK DSLR and film SLR cameras Usage Instructions: 1. Align the red marks on the adapter and lens collar 2. Turn the adapter clockwise until it locks into place 3. Attach the M42 lens Package Includes: 1 x Lens mount adapter