La Crosse Technology TX141TH-BV2 Wireless Outdoor Thermo-Hygrometer Transmitting Sensor

Wireless transmitting sensor sends accurate & fast outdoor temperature &humidity measurements with its 433MHz frequency. Place sensor in a dry, shaded location to protect from moisture build-up and direct sun exposure (may cause higher readings.) good location is on the North side of your house about 18 inches under the eaves. Weather resistant case and battery powered. To clean the base, wipe with a damp cloth. Do not use abrasive cleaners