LED retrofit kits for high bays and low bays are intended to replace inefficient metal halide and high pressure sodium bulbs commonly found in warehouses, gymnasiums, parking garages and big-box retail stores. LED high bay retrofit kits provide a longer rated life with more energy savings when compared to traditional HID bulbs. High bay and low bay retrofit lamps are super-easy to install, they screw-in the existing base with either a medium base (E26) or mogul base (E39/EX39) socket. Areas with low ceilings, can take advantage of LED low bay retrofit kits by replacing traditional metal halide canopy lights. Replace up to 400-watt metal halide bulbs with LED HID retrofit kits. There are three types of retrofits available, Type A retrofits are plug and play (ballast compatible), Type B retrofits are ballast bypass only, and Type C retrofits are ballast bypass with an external driver attached.