This Yashica Yashinon DS lens is a high-quality, manual focus lens with a maximum aperture of f/1.9. It is compatible with M-42 mount cameras and has a focal length of 50mm. The exterior material is made of aluminum and it is manufactured in Japan. The lens is part of the Yashinon series and is a standard, high-quality type.  This unit is perfect for any photographer looking to add a reliable, versatile lens to their collection.