Heating Zones with Hand Warmer: Carbon fiber heating elements powered by Li-battery creates and distributes warmth to the chest, back, and hand warmers in front pockets. One-press LED controllers allow users to control the hand warmer and body warmer respectively, and choose from 3 heat settings, delivering ideal heat for any situation. 10000mah power bank included. Available sizes: M, L, XL, XXL, XXXL and XXXXL