This Mamiya-Sekor 50mm f2.0 lens has an M42 thread mount, made to fit the 500TL/1000TL cameras of the mid-to-late 1960's. The M42 mount is compatible with Pentax cameras of that age (Spotmatics and the like) and many models from Praktica and Chinon.
The lens is in overall nice condition; the glass is good, aperture ring smooth, blades clean and focus is pretty smooth. It focuses perfectly out to infinity and has a slight slip on the way back but it is not an issue. The lens includes front and rear baps. Ships via USPS Priority Mail.