Light Efficient Design is now offering a selection of LED retrofit lights that are metal halide ballast compatible. This includes both wall pack/shoe box style light fixtures as well as overhead low bay/high bay utility lights. They offer the same benefits as the other LED lights, such as lower maintenance costs, a longer lifespan, and greater energy efficiency. The difference is these lights have the added bonus of plug and play capability, saving you from having to rewire the fixture and bypass the ballast during installation. These lights do not use direct line voltage.

This line of LED retrofit lamps is designed to work only with probe start and pulse start magnetic metal halide ballasts. Ballasts help to control the amount of current flowing so the power level is not too high. Ballasts also introduce the voltage needed to turn on the light, which is why these lights are not listed with a rated voltage. Light Efficient Design's MH ballast compatible lights also feature active cooling through the use of a 70,000 hr Sunon Mag-Lev fan, which helps to preserve the light's lifespan by maintaining a safe temperature. Most have E39 Mogul bases, but a couple versions are available with the E26 Edison base. They come in 4000K cool white or 5000K/5700K daylight color temperatures.

These lights prove useful in a number of different applications, However, due to the cooling fan, it is not recommended that they be used in areas that need to provide a more silent atmosphere. They work well in municipal and security lighting, in parks, on college campuses, along roadways, and in parking lots. Keep in mind that using a plug and play LED will not have much effect on the maintenance of the ballast. It's also important to make sure the lights are compatible with the type of ballast you have. A number of direct line voltage ballast-bypass LED lights are also available, including a few with external drivers, should it be necessary to use that method. Many of the PL lights are also compatible with electronic or magnetic ballasts, or can be used with direct line voltage.