Acuity Brand I32 Fluorescent Emergency Ballast Input Voltage 120/277 V Number of Bulbs Supported 1 Max Bulb Watts 28 W T5 T8-T12 Ballast Bulb Type Initial Lumens 500 lm Galvanized Steel Housing Material 9 1/2 in Length 2 in Width 1 in Height Low Profile 90 min Emergency Illumination Time 24 hr Recharge Time