GE Lighting 23671 GE232-120-N 120-Volt ProLine Electronic Linear Fluorescent T8 Standard Instant Start Ballast 2 or 1 F32T8 Lamps 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