Optical block of LOMO (LOOMP) 2.5/28mm lens OKS1-28-1, #645373
The lens was made at LOOMP factory (renamed to LOMO bit later) in 1964.
The lens purposed for 35mm film movie cameras (16x22mm frame size). Back focus is quite short, so it will not reach infinity focus in SLR cameras. Will work perfectly on hybrid (non-reflex) cameras on the other hand.
This is optical block only - diaphragm mechanism and control ring is here, but you need to add some sort of focusing mount. Or you can use it as replacement for your broken glass.
Bit used condition. Mechanics work fine. Glass is clean and clear.