The worst part of riding in the cold is when your toes get wet and feel frozen. The Firstgear 12v Heated Sock liners prevent just that, with female adapters to pair with any of your heated apparel or you can plug directly to your bikes power source. Simply pull this over your socks, plug them in and enjoy the heat.; Left and right labeling Thin carbon fiber heating elements Coil free 4.1-Watts per sock/12-Volt Two-year manufacturer's warranty