California Heat's Heated Pant Liners are designed to be worn under outer pants, rain gear or chaps with only a single thin base layer. Their unique heating system allows you to wear your favorite outerwear while still providing the comfort of heat. Heated liners begin warming your body within seconds using any 12V DC power source by connecting directly to the battery or the 12V accessory outlet. California Heat's advanced heating technology allows you to maintain a constant level of thermal comfort at high speeds or altitude. Wind-resistant, water-repellent ripstop nylon. Very lightweight and highly compressible garment. Sized to fit snug to your body under your outer pants. Sock plug pockets at the bottom of pants to easily connect heated sock liners or insoles. Male plug in the top left pocket to connect directly to a controller or to your heated jacket.