One of the easiest ways to ruin a good pair of Russell Boots is to dry them out too fast with excessive heat. This unique boot dryer circulates warm air throughout your boot to remove moisture quickly and efficiently. Will not damage footwear even if left on indefinitely. We use ours daily even when our boots are not wet, as it helps to dry the natural moisture from your feet. Also safe for canvas, Gor-Tex® and rubber bottom footwear. Made in the USA.