GE 13923 - MVR400/VBU/XHO 400 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 GE ED37 bulb, 400W, Base: E39 Mogul Screw, Rated Life (hours): 20000, Color Temp: 4000K, Luminous Flux (LM):