Honeywell T87K1007 Round Mercury-Free Heat-Only Thermostat Heat, White

The Round® Mercury Free Thermostat with manual changeover and R,W,Y terminals for single stage heating systems   Mercury Free Classic Styling Premier White® Separate temperature setting and thermometer The T87K heat only works with 2 or 3 wire heat only systems The Easy-To-SeeT has enlarged scale and raised numbers--plus it click at every 2 degrees Fahrenheit change FEATURES: Description- The Round® Heat Only Mercury Free Thermostat Application- Heat Only Mounting- Round Color- Premier White® Stages- 1 Heat Power Method- Uses stored power from heating controls. Terminal Designations- R, W, Y Switch Type- Relay Accuracy (F)- 2 F Accuracy (C)- 1 C Dimensions (in.)- 3 11/16 in. diameter x 1 3/4 in. deep Dimensions (mm)- 94 mm diameter x 45 mm deep Setting Temperature Range (F)- 40 F to 90 F Frequency- 60 Hz;50 Hz Cycles per Hour Adj.- 1,3,5,9 Heat Current- 0.02-1.2A running Sensor Element- Thermistor Operating Humidity Range (% RH)- 5 to 90% RH (non-condensing) Voltage- 20 to 30 Vac