Quietly and efficiently power 400-watt metal halide and high pressure sodium lamps with a 400-watt ION® Electronic Ballast. This versatile 120-volt/240-volt workhorse features 250-watt, 400-watt and Super Charge settings for propagation applications as well as encouraging aggressive plant performance. Integrated circuit and thermal overload protections provide peace of mind, soft-start technology reduces lamp stress, and ignition delay resolves spikes in power draw when firing multiple units simultaneously. This ballast is RF-shielded, generator-ready and compatible with a multitude of reflectors and lamp cords. Each ION® Ballast includes an 8-foot, 120-volt power cord (240-volt cord sold separately) and a warranty of three full years. The ballast housing is 11.5 inches by 4.5 inches by 3.5 inches, excluding the removable handle.