Original Item: The US nomenclature is SIGNAL, ILLUMINATION, AIRCRAFT AN M53A2 TRACER, DOUBLE STAR. The signal consists of one red star, one amber star, and an amber tracer element. A band of yellow Ts indicates the amber trace, one band of red Cs for a red star and another band of yellow Cs indicates an amber star. This is a particularly complicated signal. The cartridge case is aluminum and can be reused. Original 37-mm flare cartridges are EXTREMELY RARE. US-issue 37-mm flare cartridges are compatible with British-issue 1½-inch flare pistols. Not guaranteed to ignite.