F1-Digital Controller Features: 1. Suitable for two-pipe air-conditioning system; 2. Monitor two-line/ three-line motorized valve; 3. Match with digital thermostat to control room temperature; 4. Supply power auto shift to 90-240VAC, short-circuit protection function; 5. Control fan speed of fan coils: High, mid, low, auto fan 6. 18months Guarantee, ISO9001, CE, FCC