H39 TYPE MERCURY VAPOR LIGHT BULB - 175 WATTS - MOGUL BASE - DELUXE WHITE GLASS - LONG LIFE 24,000 HOURS - Supra Life mercury vapor lamps are engineered to offer top performance, energy efficiency, and long life with the lowest operating cost available. Supra Life mercury vapor lamps have the flexibility to operate in any position, in open and closed fixtures, without reducing lamp performance.