Milwaukee® M12™ Heated Hand Warmer: Powered by M12™ REDLITHIUM™ Battery Technology, Milwaukee® M12™ Heated Hand Warmers integrate (2) carbon fiber heating elements between a durable wind and water resistant exterior and thermal fleece liner to heat your hands and help maintain dexterity. Insulated dual-cuff construction combines with your outer layer to form a wind-proof seal and keep the weather out, even on the coldest days. Featuring dual-cuff construction that forms a wind-proof seal in combination with your outer layer, the hand warmer reduces the need for bulky gloves on or off the jobsite.