The Tekmarnet® Thermostat 553 is a Communicating Touchscreen Thermostat Designed to Operate Two Heating Stages, One Cooling Stage, a Fan And Relative Humidity. The Heating Stages Can be Hydronic, Forced Air or a Single Stage Heat Pump. The Cooling Stage is Either an Air Conditioner or Heat Pump. There Are Two Auxiliary Sensor Inputs Available to Measure Room, Floor, Outdoor, Coil or Duct Temperature. The Optional Floor Sensor Allows Precise Heating of Radiant Floors by Controlling The Floor Temperature And Maintaining The Desired Room Air Temperature. Relative Humidity Level Can be Measured And Controlled Using The Built-In Humidity Sensor. The Large Touchscreen Allows You to Easily Adjust 7-day Programmable Schedules And Room Temperature to Optimize Comfort And Energy Savings. The 553 Can Connect to Tekmarnet® Controls Using Two or Four Wires or it Can Operate as a Stand-Alone Device. For Further Information And up to Date Literature Visit: Tekmar Documentation | Tekmar Controls | 553