This MAMIYA/SEKOR SX 1 : 2 F = 50MM AUTO lens is a high-quality standard lens that can be used with an UNKNOWN brand camera. The lens has an aperture of f/2 and a screw mount. It is made of durable aluminum that ensures longevity. With a focus type of Auto, this lens is easy to operate and produces sharp, clear images. The SEKOR SK model is compatible with 49mm filters and lenses, making it versatile for various photography needs.