1.Household 2.Theory Temperature Sensor 3.Color of housing :white, silver, gray and other b.acklight color:blue, ... unit control, 2pipe,4pipe optional back-lit illumination programmable ProgrammingChoice of 7 day, 5/2 day programmable ornon-programmable (installer selectable ... , 60pcs/caton* Inner box size: 13x13x7cm* Carton size: 68x28x43cm T8100AC series of touch screen thermostat