SYLVANIA Quicktronic ProStart T5HO ballasts operate high output, HO Circline, and other T5 lamps with full lumen output and optimal system performance, providing nearly twice the light output of T8 systems with the same number of lamps, allowing many new design options. The SYLVANIA 49161 electronic fluorescent ballast operates (4) F54T5/HO lamps at 120/277 input volts. Ideal for use in normal light areas, this programmed start ballast is typically used in offices, board rooms, and retail.