Advance Electromagnetic Fluorescent Ballast, Series: Standard, 40 W Lamp, 120 VAC, 0.53 A, 60 Hz, Rapid Start, 50 deg F Minimum Starting, Total Harmonic Distortion: 0.15, Power Factor: 0.55, 1 Lamp, Thermal Protection: Class P, Ballast Factor: 0.63, Metal, 6.5 in L x 1.94 in W x 1.38 in H