50 WATT HALOGEN PAR 20 SPOT 4,000 HOUR LIGHT BULB - Industrial Grade halogen lamps use a rigid quartz capsule for durability that ensures precise beam control through solid state design, while providing 13% energy savings compared to standard halogens. A unique coating on the reflector allows the heat to escape from the back of the lamp while directing light out the front. Rated at 4000 hours, Industrial Grade halogens will last and average of 8 months in commercial and retail applications, while providing up to 4 years of life in normal household applications.