The PO 3.5x21P is a battery-illuminated Soviet medium-range sight with x3.5 magnification, designed and produced by BelOMO Laboratories in Minsk. Unlike the PSO-1 Optical Sniper Sight, this optical sight is designed to be fit to an Assault Rifle âš¡ or Carbineâš¡, helping improve the hit probability of the average rifleman. However, because it is an expensive, bleeding-edge technology, its current use is limited to the Spetsnaz and similarly elite forces of The Union of Soviet Socialist Republics. It can fit any weapon with a Moscow Pact (MTO) dovetail rail.