White Rodgers Heating and Cooling Mechanical Thermostat works with most single-stage heating and cooling systems, including 24 volt and millivolt setups. It is compatible with standard heating and cooling, standard heat only, millivolt heat only (such as floor or wall furnaces), standard central air conditioning, gas or oil heat, electric furnace, and hydronic (hot water) zone heat with 2 wires. This thermostat is easy to install and use, with mounting hardware and an installation guide included. It is mercury and comes with a 1-year warranty. The voltage is 24V, and the color is off-white. The package quantity is 1, and it comes in a clamshell package.