Read the temperature inside an environmental chamber or clean room without opening the door. Mount the sensor outdoors (the sensor is weatherproof), in green houses, warehouses, air ducts and other hard to reach places and continuously monitor their ambient temperature from a remote location. The wireless sensor broadcasts the temperature to the monitor from up to 100 (30M) away without obstructions via a wireless RF signal. The monitor displays either the local and remote temperatures in °C or °F, has min/max recall, audible and visual alarms, and indicates when the batteries are low in both the sensors and monitor. Each monitor comes with 1 temperature sensor with bench stand and wall mount, batteries (2 x AA + 2 x AAA) which last about 1 year. The monitor will read up to 3 temperature sensors (click here for additional sensors), with the additional sensors sold separately.