This is the first 15mm viewfinder released by Nikon to accompany the original UW-NIKKOR 15mm lens.

This version is distinguished by a machined band around the body. In addition, the four screw mounting point is flat where later mounting points were curved.

Interestingly, this viewfinder was used in numerous official Nikon photographs advertising not only the Nikonos II, but also the Nikonos III and IV-A cameras with later versions of the 15mm lens.

These viewfinders are considered extremely rare, especially in good condition.