Night vision scope - a relatively low-tech (gen.1) Russian version. It's useful for enhancing human vision when investigating under low-light conditions, indoors or out. You can see into the dark shadows with it, but not in total darkness.

This unit takes the old-style screw-mount camera lenses, so the Zenit 50mm lens can be swapped for a Pentax wide-angle or telephoto for a different view.

The unit has a light amplifying tube, powered by a 9V battery. The image is green, the colour band the eye is most sensitive to. It is infra-red sensitive, but passive, not having its own IR light source.