The Philips ICN-4S54-90C-2LSG35I is a ballast used to power a maximum of four T5 and T5HO lamps. It controls the current protecting fluorescent lights from overheating and burning out. It is compatible with 120/277 volt electrical connections. Ideal for lamp models F54T5, F54T5HO and Plug-in CFL lamps of 36-58W each.