Honeywell T87N1000 Heat/Cool Thermostat, White None Made in USA 5-Year Warranty The easy-to-see face has enlarged scale and raised numbers - -plus it click at every 2?F change Mercury Free Classic Styling Premier Whit Separate temperature setting and thermometer The T87K heat only works with 2 or 3 wire he Mercury Free No Batteries Required Temperature Range; 40 to 90 degrees Fahrenheit