Integrated carbon heating element under the toe bed. Up to 8 hours of heat 85% Merino wool blend. Extra thick comfort foot bed and arch support woven in. Over the calf height. Wireless remote-control settings of Low-Med-High-Off. Thin profile 3.7v 4000mAh batteries. Instant heat when you need it, and easily adjust the heat comfort with a wireless remote. A blend of 85% merino wool blend with spandex and elastic will help keep these socks above the calf. The battery pocket sits high enough to use comfortably with most alpine boots. Left & Right battery pocket located on the outside of each sock. Packaged in a reusable storage box. Includes: 1 pair XTREMEHEAT socks, 1 remote control with battery, 2 rechargeable Li-Po batteries, 1 AC charger with dual mini USB cables, Instruction manual.