AcuRite Plastic Wireless Indoor & Outdoor Thermometer & Humidity Gauge reliable and accurate temperature and humidity readings, transmitting data every 30 seconds to keep you informed in time. Designed for both indoor and outdoor use, it measures temperature ranges from -40°F to 158°F, making it suitable for a variety of environments. The device features a large, easy-to-read display with a trend line that highlights daily highs and lows, helping you monitor changes throughout the day. Its enhanced wireless sensor has an impressive 165-foot range and can transmit signals through walls more effectively. The main unit operates on 3 "AA" batteries, while the sensor uses 2 "AA" batteries; batteries are not included. Compact and practical, the thermometer measures 3-1/2" wide by 5-1/2" high, making it a convenient addition to your home or office.