This heavy-duty dryer uses constant-temperature "forced air" technology to gently dry ! Dry and warm boots and gloves together! The heavy-duty works quickly to remove moisture and perspiration. This heavy-duty will not harm breathable hypalon, or other linings, neoprene, polyester microfiber materials, woven nylon, expensive leather, canvas, vinyl, rubber, plastics, or, other man-made materials. Enjoy warm, dry, comfortable boots and gloves with no stiffness, no shrinkage and no damage whatsoever