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 Make M42 mount lenses (Zeiss, Pentax, Praktica, Mamiya, Zenit) can be used on Pentax PK cameras There 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. Material: Brass P.S.: Although the lens will fit physically, automatic diaphragm, auto-focusing, or any other functions will not operate correctly while using this adapter. In this case "stop-down mode" will need to be used when metering since the lens does not have the ability to have its aperture controlled by the camera body. You can shoot with manual mode or aperture priority mode(A/V). Suitable For: Lens: M42 Camera: forPentax PK DSLR and Film SLR Usage: 1.Put red marks of the adapter and lens collar together. 2.Turn the adapter clockwise till the fixative click. 3.Set M42 lens. PackageIncluded: 1 x Lens mount adapter _x000D_