This is a lens hood for a Nikon 55mm F1.2 single-focal-length old lens. It's the common Nikon 52mm diameter, so it could be used with other old Nikkor lenses. It's listed as junk because there is distortion in the mounting area. It can still be attached, and I was able to use it within my own usage, but it is still junk. Please order this assuming you are receiving a hood-shaped object.