Suitable For: M42 Lens Mount (Zeiss, Pentax, Praktica, Mamiya, Zenit) PENTAX CAMERA: *ist D, *ist ... , *istDL2, K100 Introduction:M42 to all Pentax PK mount adapter ring. Make M42 mount lenses (Zeiss, Pentax, Praktica, Mamiya, Zenit) can be ... W-TIANYA adapter ring Pentax M42 42mm to PK K Mount Adapter Infinity focus for K20D K100D K200D DC141