Universal Vertical Heat/Cool Mechanical Thermostat White-Rodgers' Mercury free mechanical thermostats are both economical and environmentally friendly, featuring enclosed snaps and a built in bimetal thermometer for a more reliable performance. Product Features: Replacement for hundreds of White-Rodgers and competitive models installed during the past 50 years Enclosed contacts for increased reliability and accuracy Heating or cooling 3-wire zone mounting plate included Mercury free 5-year warranty White-Rodgers is the world"™s leading provider of heating, ventilation, air conditioning, and refrigeration solutions for residential, industrial, and commercial applications. Combining technically superior products and services from industry-leading divisions and brands with global engineering, design, distribution, installation, and monitoring capabilities help White-Rodgers to create reliable, energy efficient climate systems that improve human comfort, safeguard food, and protect the environment.