Zenitco B-51 PKM Top Rail is compatible with all models of
the Kalashnikov machine gun. B-51 gun is a milled product made of aluminum
alloy D16T with a black coating. It is mounted on the cover of the receiver of
the Kalashnikov machine gun by replacing the standard hinge axis of the
receiver cover on the axle supplied with the bracket B-51. The installed
bracket B-51 forms 19 x Picatinny bars over the cover of the receiver of the
PKM, which does not overlap the line of sight when using standard iron sighting
devices.