PHILIPS 75W ED55 Medium Base Coated BD17 HID Mercury Vapor Light Bulb

Mercury Vapor lamps feature low initial cost, but have higher operating costs than HPS or Metal Halide due to its lower efficiency. The clear mercury bulb has a bluish green appearance and the Deluxe White has a higher color rendering. Mercury lamps get dimmer over time and rarely burn out, so it is wise to replace them and restore light level.