SYLVANIA 64575 - 400 Watt - ET18 - COMPACT METALARC - Metal Halide - Tubular Envelope - Unprotected Arc Tube - 4000K - ANSI M59/E - Universal Burn - M400/U/ET18 Color/Finish: Clear Color Temperature: 4,000K Average Lifetime: 20000 hours Lumens (light output): 36000 CRI: 65