A must for all wood or coal burners. Gauge indicates how hot the stove is at any given time, taking the guesswork out of knowing when to refuel. Works with a bimetal spring and includes a magnet and tapping screw to safely secure it to the stove or stovepipe. Used for refueling. Compatible with all wood or coal burners. Magnetic with tapping screw mount. Dimensions 2-1 2D x 2-1 2W x 5H, weight 1.