NEW PRODUCT! Celsius Scale Probe Thermometer (3-38) Measures temperatures, in Celsius and Fahrenheit degrees, inside the flue pipe of the woodstove. Installs easily through a 0.6 cm hole. Metal probe stem (10 cm long) is engineered to accurately measure temperatures up to 900&deg; C for any diameter stovepipe up to 20 cm. Silver zone indicates burning too cool and danger of creosote. Red zone shows burning too hot and wasting wood. Black zone is optimum temperature for most brands of wood burning heating stoves. Made by Condar in USA. Mounts easily 4" probe Fahrenheit AND Celsius scales Reads up to 900 degrees Celsius Made in USA