50W LED Retrofit Lamp for replacing HID lamps up to 175W, 120 - 277 Volt, E39 base, Approved by UL for enclosed fixtures, Active cooling is provided by long life "Mag-Lev" cooling fan which keeps LED's cool even when operating within enclosed light fixtures. UL1993 certified and UL1598C classified for USA and Canada. Note: UL1598C keeps UL approval for fixture after ballast is removed or wired past. Available in Daylight (5000K), Cool White (4200K), or Warm White (2700K).