Exceptionally warm and comfortable. Made from 45%Acrylic - 32%Wool - 22% Nylon - 1% Rubber. Battery snap pouch pocket for battery storage. Wool blend provides superior moisture control. Heel/toe reinforced for lasting ruggedness. For best lasting care, hand wash - do not wring sock, simply hang or lay flat to dry. All over cushion for absorbing shock and abrasion prevention.