Bomb Sight, Sighting Head for T-1 Bombsight System F4U Corsair the faceplate rotates to indicate

the faceplate rotates to indicate the selected frequency within the small metal frame (to which a small lamp could be affixed for illumination)

on the underside of the base Russian Cyrillic characters are stamped in the metal

was electrical

automatic Type K-4 Computing Gun Sight used in the Sperry ball turret in WWII-era heavy bombers such as the B-17 Flying Fortress and B-24 Liberator

Bomb Sight, Sighting Head for T-1 Bombsight System F4U Corsair the faceplate rotates to indicateThe World War II T 1 bombsight system was originally designed by the British (as the Mark XIV bombsight) and first entered service in 1942. It was used in versions of the US Army Air Force B 24 Liberator, B 25 Mitchell bombers, as well as the British Avro Lancaster and deHavilland Mosquito bombers. This T 1 Sighting Head was made by AC Spark Plug division of GMC. The system included a sighting head connected to a mechanical (pneumatic) computer.