Philips Lighting 300 W Halogen Projector Lamp, GY5.3, 120 V, 50.7mm

Quartz halogen lamps with integral reflector, which serves as an efficient mirror condenser system. The dichroic coating on glass reflector radiates about 75 of the generated heat backwards, keeping temperatures within safe limits. The halogen burner is precisely aligned using an optical system, so no realignment is needed when the lamp is replaced.

High efficacy gives low energy consumption
Negligible depreciation in light output during lifetime