Kiev-10

in general it is quite a unique Soviet camera. Alas, in fact, this model was not developed, it was produced at the Kiev Arsenal plant from 1965 to 1974. Staffed with a lens Helios-81 Automatic (devices of late years of production).

the camera had its own unique bayonet. The built-in exposure meter (like the Zenith E) is located on the front wall of the pentaprism. The camera had a unique fan-type shutter with metal curtains.

But alas, the plant was not able to develop this very interesting site (the ideological prototype could serve as the gates used on the Nikon cameras of the first half of the 60s).
The bayonet used on the Kiev-10 apparatus was later used on the Kiev-15 / 15TTL camera. And with the transition to the Kev-20/17 series, the plant equipped its apparatus with bayonet H, compatible with Nikon's optics.