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 operated (not included) and 90m wireless range (no obstruction) from wireless transmitting sensors (TX141TH-BCH)