Non-Programmable Thermostat For Home Single-Stage Systems, 1, Blue Backlight High Compatibility: Forced air (gas, oil or electric), Electric furnace, Hot water steam or gravity radiant heat, Heat only systems, Heat pump w/o auxiliary or emergency heat, Millivolt, Gas fireplaces (24V), Floor or wall furnaces, Cool only systems.(TIP: Before purchasing, check to see if this thermostat is compatible with your system.) Not Compatible: Heat pump with auxiliary or emergency heat, Dual fuel/hybrid heating, Electric baseboard heat (110-240 volts), Line voltage, Convectors, Radiant-ceiling heat, Mini split systems and 12V RV systems. Easy to Install and Use: Large terminal blocks with universal sub-base, can be installed within 30 minutes, clear, easy-to-read backlight LCD display and easy controls make for a user-friendly experience. Simple but Powerful Control: Easy-access front-load battery compartment, adjustable temperature differential (swing) for energy optimization and maximum system life, Support temperature display calibration, Convert C/F units, compressor delay protection (selectable on or off). Dual Power Supply: Can be powered by 24VAC power or 2 AAA batteries, No common wire (C-wire) required on most systems (only required on heat only and cool only systems).