Description Electric powered, single cylinder piston air compressor power unit for gyros in stabilized gunsight Mark 14. Used with 20mm Oerlikon gun mounts, Mk 51 Directors or 40mm Single gun mounts, this unit provides clean, dry air at regulated pressure to power the gunsight gyros. On a 20mm mount, the power unit would be mounted directly underneath the gun shield. Includes motor, compressor, bypass valve pressure regulator, intake and outlet fittings, air drier (on the outlet), two electrical connectors, electric power switch and fuse block, (power for the gun sight reticle lamp and the oil heater is routed through the switch on the power unit) and air pressure gauge. The gauge would be in the green zone, or between 6 and 8 PSI, for proper operation. Two wing nuts and swing bolts permit opening the compressor housing for servicing the pressure regulator and valves.