WHITE RODGERS S28-16 1F58-910 HEAT PUMP THERMOSTAT SUBBASE ONLY SUBBASE ONLY / FOR USE WITH:1F58-910 RANGE:50 TO 90 DEG F (10 TO 32 DEG C) / VOLTAGE:30 VAC MAX RATED DIFFERENTIALS:STAGE 1 HEAT:1-1/2 DEG F / STAGE 2 HEAT:1 DEG F / COOLING:1-1/2 DEG F DIMS:5-3/4&quot;L X 3-1/4&quot;W X 7/8&quot;D