Low Voltage Thermostat, Terminal Designations R, W, System Switching No, Fan Switching No, Automatic Changeover No, Dual Transformer Compatible No, Power Method Hardwired, Voltage 20 to 30V AC, 750mV Compatible Yes, Mounting Vertical, Height 4 1/2 in, Width 2 3/4 in, Depth 1 1/2 in, Color White, Control Range 50 Degrees to 90 Degrees F, Features Mercury Free, For Use With Millivolt, Standards NEC Class II. This item has been restricted from sale in the following state (s): []