Wireless thermo-hygro sensor for use with compatible La Crosse Technology 915 MHz weather stations;Small LCD for on-site temperatures; transmits to a receiver at 915 MHz frequency from up to 330 feet unobstructed;Assesses outdoor temperatures from -39.8 to 139.8 degrees F and relative humidity levels of 1 to 99 percent; also suitable for indoor use;Requires separate purchase of a compatible base and 2 AA batteries; mount with provided bracket in sheltered location;Measures 1-1/2 inches wide by 5/6 inch deep by 5 inches high; limited manufacturer warranty