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 ythe hands and help maintain dexterity. Insulated dual-cuff construction combines with ythe 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 ythe outer layer, the hand warmer reduces the need for bulky gloves on or off the jobsite.