Wireless transmission range: This sensor ranges up to 330ft(100m) in an open area. To ensure proper synchronization, insert the battery into the main unit before inserting the battery into the sensor.
Temperature and Humidity range: Temp: -40℉ to 140℉; Humidity: 1% to 99%. We recommend to use the low-temperature resistant batteries in winter as the performance of normal batteries will be weakened and affect the sensor signal strength when the temperature is below 14℉.
Powered by replaceable 2 x AAA batteries (not included), you can easily find them on the market.
Note: We recommend ①place the sensor upright ②place it outdoors with a shelter ③make it far from interfering sources ④ put it at least 47inches (1.2m) from the ground.