LCD Display Air Conditioning 2-Pipe Programmable Room Thermostat for Fan Coil Unit About the product 1. Acrylic lens to avoid the finger scratch 2. Touch Button makes simple operation 3. Large screen display with backlight, easy to read, even in the dark 4. Four periods program schedules maximize comfort and economy 5. One-touch temperature control overrides program schedule at any time 6. Precise comfort control keeps temperature within 1 Celsius Degree of the level you set 7. Data memory when power is off 8. Easy installation 9. Designed to on off control the fans and valves in air conditioner applications via comparison of the room temperature and setting temperature to achieve the aim of comfort and saving energy Model Definition of Thermostat A1: Two pipe: Control fan coil unit and two wired motorized valve. (When room temperature reaches the setpoint, both will turn off) A2: Two pipe: Control fan coil unit and two wired motorized valve. (When room temperature reaches the setpoint, valve will turn off but fan will turn to low speed) B: Two pipe: Control onoff motorized damper C: Two pipe: Control fan coil unit and three wired motorized valve M: Two pipe: Control 0-10V motorized valve E: Four pipe: Control fan coil unit and two wired heat and cool motorized valve T: Clock L: Backlight P: Weekly programmable K: Keycard E: Eeternal sensor P and N could not be compatible at the same time