This is a very unique bulb. 2 Filament, 21 candle power and 6 c.p. The bulb is angled 45 degrees from the pin. It has a bayonet base 19/32" diameter. The bulb diameter is 1-1/8" and length is 1-7/8" silvered except for 7/8" diameter frosted window. We believe they were made to be used in some microscopes or microscope light assemblies. A rare find One of our customers advises that this bulb was designed for and used in the US Navy WWII Illuminated Sight Mk 8 and the Mk 20 gunsight. Thanks Ross. Another advises that this is for the gun site used in a A-26A aircraft. Thanks Larry.
