-  Reduced size and weight with increased capacity and longevity

   -  4400 mAh capacity offers a category-best 18 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. Just what one would expect from HOTRONIC

   -  The new "Welded" wires allows for a seamless sock for a better fit with more comfort

   -  Material: 54% polyamide, 25% elastane, 21% wool (merino)

The Heat Sock Set XLP 2S BT Surround Comfort is the pinnacle in warmth, performance, and longevity. Combining a pair of HOTRONIC XLP 2S BT Battery Packs with the Soft Compression and Surround Heating Element of the Surround Comfort sock, and then allowing control via a Bluetooth App, HOTRONIC raises the bar with convenient Constant Heating Power when needed most - in the cold!