FeaturesNear wavelength infrared, color temperature emitted in approximately 4100 deg F (high brightness)Approximately 96% radiant efficiencyExcellent resistance to thermal shockHighest moisture resistance and quickest heat-up time3/8 in Dia clear or red quartz envelopeCoiled tungsten filament, sealed porcelain end caps, halogen gas filled5000 hr life expectancy of all heating elements25 in L heated