Honeywell Economy Mechanical Thermostat reliable low voltage control for gas or oil heating and cooling systems. Featuring a bimetal temperature sensor and a snap acting magnetic switch, this thermostat ensures simple and worry- operation without the need for leveling and is mercury- for safety. It includes a dual temperature scale in both Fahrenheit and Celsius, along with a decorative backplate for an attractive installation. Available in two models, one designed for heat only and the other for both heating and cooling, each comes packaged in a convenient clamshell. This thermostat combines ease of use with dependable performance for your home comfort needs.