The Gavita Pro 1650 LED ML is 1650 µmol s-1 fixture with an efficiency of 2.6 µmol s-1 per watt. ML stands for Multi-Layer, as the array of LEDs provides a uniform spread of light at short distance to the crop. The array configuration of 8 LED bars also allow you to use it in low rooms, over single benches, or even in 4 x 4 ft or 5 x 5 ft tents. This fixture is built with high quality 120-270 volt Philips advance drivers.