Volume 141 Catalog Page: 124, 1281H/1C conventional or 1H/1C HP no auxiliary heat20 to 30 VACAuto or manual changeoverFan: auto, onSystem: heat. off, cool, autoHeat 40° to 90F; Cool 50° to 99FDual powered: battery or hardwired4-1/16"W x 4-1/16"H x 1-5/32"DTH4110U2005/U