NEMA C78.1420-1994 Dimensions of Centering Systems for Projection Lamps - Two-Inch (51 mm) Integral Reflector Rim Reference Tungsten - Halogen Lamps with GX5.3 Bases
2001NEMA C78.1420-2001 Electric Lamps - Microfilm Projection Lamps - Two-Inch (51 mm) Dichroic Coated Integral Reflector, Rim Reference, Tungsten Halogen Lamps with GX5.3 Bases
1997NEMA C78.1420-1997 Electric Lamps - Microfilm Projection Lamps - Two-Inch (51 mm) Integral Reflector@ Rim - Reference Tungsten-Halogen Lamps with GX5.3 Bases (Frist Edition)
1994NEMA C78.1420-1994 Dimensions of Centering Systems for Projection Lamps - Two-Inch (51 mm) Integral Reflector Rim Reference Tungsten - Halogen Lamps with GX5.3 Bases