This standard defines the dimensional limits and other physical characteristics required to ensure the interchangeability and to assist in the proper application of a specific category of lamps. This category is tungsten-halogen lamps with G6.35@ GX6.35 and GY6.35 two-pin bases and 27.0 to 40mm nominal light center length. Lamps of various design voltages are included. Lamps with the specifications listed in this standard are intended for projector applications. The grouping of lamps in this standard is based on general physical characteristics. It does not imply that the lamps listed are interchangeable with each other in a particular application. Certain lamps in this standard are compatible with IEC 357.