Volume 141 Catalog Page: 124, 1281H/1C conventional and 2H/1C heat pump7 day, 5-1-1 day, 5-2 day or Non-programmableFor gas, oil & electric heating/cooling40-99° temperature rangeLED back light for easy viewingBattery or hardwire power method with manual changeover24 volt4-1/16"" square thermostatTH4210U2002/U