HOTRONIC XLP 1S BT Surround Comfort Evo Heat Socks Set (01-0100-378)

The best size to capacity ratio on the market today; Battery Pack XLP 1S BT - High-performance, low-weight Li-ion battery in a compact design; 2200 mAh capacity offers a category-best 10 hours of constant heating power; Bluetooth app controls the Battery Pack from any smart phone; Merino wool helps wick moisture away from feet and promote warmth; Surround Heating Element envelopes the toes; Safe, stable, and reliable; The "Welded" wires allows for a seamless sock for a better fit with more comfort; Material: 54% polyamide, 25% elastane, 21% wool (merino)