Standard Instant Start T8 Ballast will accept up to 2 or 1 F32T8 lamps * Low profile housing and lightweight for portability * Runs quietly with most 120-volt applications, less than 10-Percent Total Harmonic Distortion (THD). less than 20-Percent with other approved lamps * High performance instant start electronic ballast is for all general fluorescent applications * Mounting dimensions: 8.9-Inch L x 1.1-Inch W, Mounting slot set 0.3-Inch apart