This is a small wide-angle lens for Pentax' KA-mount.t feels really nice to use. It feels solid, and it's all metal. The rubber focus ring and metal aperture ring have just the right knobby knurling. It works great. It's easy to focus, has great evenness of illumination even wide open and great center sharpness at any aperture. Dust specks are present. It does not affect image quality. These were made after 1983 and more advanced than the the M series. No fungus. Lens has nice contrast. Super Multi-coated.