White-Rodgers 1F56N-444

Mechanical thermostatslow voltage t-stat, mechanical nonprogrammable, stages heat 1, stages cool 1, system switching heat-off-cool, fan switching auto-on, color white, display analog, horizontal mounting, mercury free, for use with heating, cooling, heat pump without auxiliary heat, millivolt, 3-wire zone valve, includes heat only or cool only back plate, heat-cool subbase.