Fits Nikon F, AI, AF DSLR Lenses

Rear Lens Cap and Body Cap Kit for Nikon lenses, protects the rear elements of the lens when it is removed from the camera.

From Wikipedia

The Nikon F-mount is a type of interchangeable lens mount developed by Nikon for its 35mm format single-lens reflex cameras. The F-mount was first introduced on the Nikon F camera in 1959, and features a three-lug bayonet mount with a 44 mm throat and a flange to focal plane distance of 46.5 mm. The company continues, with the 2020 D6 model, to use variations of the same lens mount specification for its film and digital SLR cameras.