Supco GC506 Constant Differential Universal Replacement Control Specifications: Capillary Length: 24" Differential °F: 13°F Calibration °F: Cold On: -7°F Calibration °F: Warm Off: 48.5°F Normal Off/On Temperature: 18°F / 31°F Features And Benefits Ideally suited for "frost-free" refrigerators and conventional units. Universal mounting hardware insures controls will replace wide range of controls The GC500 series constant differential controls always maintain the same difference between on & off temperature over the range of the control.