This is an Ushio JCS 575 Watt/120 Volt Halogen Lamp. It is designed as a medium wattage alternative to the FKW 300W and FRK 650W lamps used in theatrical Fresnels. These medium wattage lamps allow for two instruments to be used on a 1200 watt capacity dimming channel while maximizing the light output. The halogen capsule utilizes a bi-plane filament design.