Ballast, Fluorescent Electronic; Lamp Type: T12, T12 U-Bend; Lamp Watts : 25-40W; Number of Lamps: 2; Lamp Starting Method: Rapid; Voltage: 277V; Primary Lamp Type: F40T12; Power Factor: Normal Power; Wiring: Series; Min Temp - deg F: 50°F (10°C); Packaging: Individual Pkg:10 (Priced per ballast); Lamp Range: (2)F25-40T12; THD Max - Percent: 0.2; Dimensions: LxWxH: 9.50x1.70x1.18 in (24.1x4.3x3.0 cm); Manufacturer Series: Standard