Works only with Pro1IAQ model T955W thermostat. To to four T251W can be configured to sense and display room temperature only or allow remote override. Note - 24AC required at T955W thermostat for communication with R251W Indoor Sensors. Includes mounting hardware and 2 AA alkaline batteries.
Range between the R251W and the T955W master thermostat is up to 100 feet with no obstructions and up to 50 feet in standard residential metal, brick, and concrete construction.