Flambeau Men's Heated Socks Kit Wool, Polyester, And Cotton Imported Carbon fiber heating elements designed to keep your toes warm Medium weight sock for balance between warmth and comfort Wool polyester and cotton blend to pull moisture away from feet Battery compartment designed to fit just below your calf Battery charger Included Carbon fiber heating elements Medium weight sock Wool, polyester, and cotton blend Includes (1) pair of socks, (2) 3.7V li-ion batteries, ac charger and dual mini-USB cord