Plastic, for checking indoor and outdoor climate, with indoor sensor and 3 wireless radio transmitters for monitoring temperature and humidity in up to 4 rooms, additional functions such as maximum and minimum values, trend arrows, weather forecast with air pressure, radio clock with date, day of the week (7 languages ) and alarm, scope of delivery base station incl. 3 x thermo-hygro transmitter, measuring range temperature outside -40?+60°C (-40?+140°F), measuring range temperature inside -10?+60°C (14?+140 ° F), measuring range humidity outside 1 ? 99%, measuring range humidity inside 20 ? 95%, batteries 2x1.5 V AAA (base station), 2x1.5 V AAA (per transmitter) not included