Monitors temperature and humidity from up to 90 feet away. F and C selectable. Up to three sensors may be used with base station. Includes one remote sensor. Jumbo display. Min/max memory. Trend information. Comfort indicator. Indoor and outdoor temperature range: -58 to 158 F (-50 to 70 C). Indoor and outdoor humidity range: 25 percent to 90 percent. Temperature resolution: 0.2 F (0.1 C) Humidity resolution: 1 percent. Transmitting range: up to 90 ft. Transmission interval: approximately every 30 seconds. Transmission frequency: 433 MHz. Base station uses 2 AA batteries; sensor uses 2 AA batteries. Dimensions: Base is 4.5 x 4 x 0.75 in.; Sensor is 4 x 2.75 x 0.75 in. Weight (w/o batteries): Base Station: 5.5 oz.; Sensor: 2.2 oz. Includes: Wireless Temp/Humidity Sensor. Batteries.