SPECIFICATIONS:-TEMPERATURE CONTROL: Microprocessor-optimized PIA -Heating cycles: 15 minutes -Accuracy: ± 0.5ºC / 0.9ºF (electromechanical relay)-SWITCHING ACTION: Works with electromechanical relay-PROGRAMMING: 7-day, 4 time periods/day, 2 temp. settings -Early Start function:24-hour clock / ºC or ºF - DIMENSIONS (H•W•D): 82 x 78 x 25 mm / 3.2 x 3.1 x 1 inches FEATURES:-Compact design: one of the smallest, most attractive thermostats on the market -A model controls ambient temperature -F model controls floor temperature using sensor in floor -On-screen heating power indicator gives at-a-glance verification of power being used -Temporary bypass enables temperature override without changing programming -Large, easy-to-read LCD features intuitive programming icons -Battery-free backup means no re-programming your schedule after power outage