Intellivolt Electronic Ballast, For 2 F34t12 Or F40t12 Lamps, Approved For Commercial Applications, Rapid Start, High Power Factor, Input Voltage 120V Or 277V, Input Frequency 60 Hertz, Ballast Factor .85, Ballast Efficacy Factor F34t12 1.37, F40t12 1.18, Max THD% 20%, Minimum Start Temperature F34t12 60 Degrees Fahrenheit, F40t12 50 Degrees Fahrenheit, UL Listed, CSA Certified, Compatible With Sensormatic Systems, 9.50"L x 1.3"W x 1"H, Individually Boxed.