The Wireless Indoor Sensor(s) is used to change the sensing location of the thermostat. Sense temperature and humidity remotely, average temperature, and humidify and dehumidify in separate locations.Specifications: Application: Wireless Indoor Air Sensor Dimensions (in.): 2 7/8 in. high x 1 7/8 in. wide x 15/16 in. deep Dimensions (mm): 73mm high x 48 mm wide x 24 mm deep Includes: 2 AAA alkaline batteries and mounting hardware Used With: Redesigned Prestige IAQ, Prestige IAQ 2.0, Prestige 2.0, All New RedLINK VisionPRO 8000 Mounting: Mounts on a vertical wall with supplied bracket and mounting hardware Operating Humidity Range (% RH): 5 to 90% RH, non-condensing Operating Temperature Range (F): 35 F to 114 F for optimal battery life,0 F to 120 F Operating Temperature Range (C): -17.8 C to 48.9 C,1.7 C to 45.6 C for optimal battery life Color: Arctic White Power Method: Battery