Philips 220640 - CDM-T Elite 315W/942 315 watt Metal Halide Light Bulb HID Bulbs produce high output for their size making them a compact powerful &amp; efficient light source HID Bulbs are used for general lighting, professional lighting fixtures, growing applications HID bulbs put out around 3-5 times greater output (lumens per watt) than traditional halogen bulbs Philips T9 bulb, 315W, Base: PGZ18, Rated Life (hours): 30000, Color Temp: 4200K, Luminous Flux (LM): 35500