... 1.Household 2.Theory Temperature Sensor 3.Color of housing :white, silver, gray and other ... 2pipe,4pipe optional back-lit illumination programmable ProgrammingChoice of 7 day, 5/2 day programmable ornon-programmable ... x 2-wire or 3-wire valve output, high, medium,low fan speed output* Ambient temperature: 0 °C [+32 ° ... size: 13x13x7cm* Carton size: 68x28x43cm T8100AC series of touch screen thermostat