1. The ballast is an electronic ballast, suitable for terrarium lamps 50W, which can work with most of HID ( High Intensity Discharge) metal halide bulbs. Recommend Bulb Brand: ZooMED HID Metal Halidebulb 50W, Exo-Terra Sunray metal halide bulb 50W and Mega-Ray metal halide bulb 50W and other bulbs from China. 2. The fixture with E27 ceramic socket. It is very easy to install PAR30 bulbs.