Nippon Kogaku 35mm f2.8 Nikkor-S Auto (pre AI) wall adapter The Nikon DK-6 is a

The Nikon DK-6 is a rubber eyecup for Nikon cameras with 22mm viewfinder threads (like the F100 and F90)

but still an excellent little pocket camera in its own right

This finder gives an accurate framing image for the Nikonos 80mm f/4 lens while on land

which is as a rangefinding accessory to a camera

Nippon Kogaku 35mm f2.8 Nikkor-S Auto (pre AI) wall adapter The Nikon DK-6 is aThe Nippon Kogaku 35mm f2. 8 Nikkor S Auto is a compact wide angle standard lens actually, smaller than the standard 50mm lens. Smooth focusing, good diaphragm, very minor haze under the front element which will not affect imaging. Please note: this is a pre AI lens and compatibility may vary on newer cameras. Check your camera's instruction manual to be sure.