FeaturesUniversal operating position45 Lumens/W luminous efficiencyHard glass bulb material350 deg C bulb temperature rating210 deg C base temperature34.5 mg mercury contentLow initial cost, but have higher operating costs than HPS or metal halide due to its lower efficiencyClear mercury bulb has a bluish green appearance and the Deluxe white has a higher color renderingMercury lamps get dimmer over time and rarely burn out, so it is wise to replace them and restore light level