Read the temperature clearly from inside. The thermometer is fitted using double-sided tape and magnets. Use the tape to attach the black ring to the outside of the window. Then place the thermometer directly over the black ring, where it is held in place by magnets. The thermometer sits in the window discreetly and elegantly and can easily be removed to clean the window. The temperature is displayed in Celsius (°C). Made of stainless steel and plastic. Dimensions: Ø 7.7 cm. Uses one CR2032 battery (included).