Safe & Energy-saving: TaoTronics® TT-AL01/TT-AL02 can replace 400W Metal Halide Lamp, saving up to 90% of your electricity bill; * LED is cold light, which is far superior to traditional florescent and metal-halide lamps; You don"t need buy additional expensive cooling system; * Built-in CE approval 97% efficiency Power supply, plug and play, no need heavy ballast as MH and fluorescent which will inefficient and burnout finally; * Environment-friendly: no mercury and other harmful heavy metal; * Long Lifetime : The high power 3w LED convert electric energy into light directly, there is no filament to break on led, so they could be more durable and nearly no maintenance, you don"t need to replace the bulbs frequently like MH/Fluorescent.