Multi-functional station shows you temperature and humidity indoors, as well as up to 3 additional rooms. Displays a smiley face for comfortable room climate (within +66.2F to 77F and 40 to 60%RH range) or frowny face, if at uncomfortable levels inside your home. Writable display (pencil only) to identify each room you're monitoring from a storage room, basement, garage or other source. From the garage to the attic, let the wireless technology leave you in comfort knowing room conditions elsewhere. Battery operation and offers a wireless range over 330 ft. (100 m) from included transmitting sensors.