The Apollo touch screen room thermostat is mainly applied the Heat pump, Gas Heating, Electric Heating, and so on systems. Features: 24VAC or Battery Powered (2 x AAA) Large Backlit LCD Touch Screen Security Logic inc Key lock & Limit Control 7 day, 5+2 Day or Manual Operation Programmable Fan Logic Heat cool & Heat Pump Logic Single & Multistage Control Remote Sensor Inputs Outside Sensor Inputs Designed and built by Smart Temp Australia Comprehensive 3 year Warranty RTB Specifications: Input Voltage (Hardwired) 20-30 VAC 50/60 Hz Relay Rating 24 VAC @ 1 Amp Max Per Relay Battery Power (2) AAA 1.5 V Operating Temperature 0° C to 55° C Operating Relative Humidity 0-95% (non-condensing) Storage Temperature 0° C to 65° C Size: 125" W x 85" H x 25" D (mm) LCD Display Size 57 W x 99 H (mm) Back Light White LED Short-Cycle Delay Off or 4 minutes Displayed Temperature Resolution 0.1° C Set Point Range Heating 5° C - 49° C Cooling 6° C - 50° C Heating and Cooling Limits Fully adjustable Onboard Sensor NTC type 3 100K Remote NTC type 3 10K Warranty 3 years (RTB).