Keep your feet warm and comfy with our thin but extra durable heated sock liners that provide all day heat on a single charge. Made with a moisture-wicking micro polyester to keep your feet dry and spandex interlock fabric that forms to the foot for a great fit. Includes two small, powerful rechargeable VPS826HV lithium batteries, dual charger and wireless receiver/remote. Each VPS826HV 2600mAh battery weighs just around 2 ounces and discreetly tucks into a small storage pocket with hook and loop closure on the side of each sock. The socks come with a microprocessor controller with 3 power level settings that can be controlled manually or with the included remote. On the highest setting, the socks will provide over 7+ hours of soothing warmth to the bottom of the foot.