The Pentax - M SMC 50mm  is the standard focal length partnering lens with the Pentax K1000. At max aperture F1.7 an excellent choice for light challenged scenes.  Optically and cosmetically in very good condition.  You can buy this lens for your K-mount Pentax or choose the option of adding a K&F precision PK-E adapter which enables this lens to be mounted on Sony E-mount, focus peaking cameras. Both lens cap.

Pentax-M 50mm F1.7 K mount S#3204972