Heat Factory Mid-Calf Socks with Foot Heat Warmer Pockets, Mossy Oak/Olive One pair wool blend socks provides protection and instant, long-lasting warmth for your body in cold outdoor activities Socks constructed with cushioned arch and reinforced heel; above-calf length Mossy Oak pocket sewn in above the toe holds disposable foot warmer that last up to 6 hours; two Heat Factory Foot Warmers included Medium fits men's US shoe sizes 5- 8; Large fits men's US shoe sizes 9 - 13 Wool blend: 19% wool, 49% acrylic, 10% polyester, 11% nylon, 9% olefin, 2% spandex One pair of wool blend socks with Mossy Oak pocket sewn in above the toe, holds disposable Heat Factory foot warmer Provides extra warmth along with a moisture-protection layer One pair of Heat Factory 6+ hour foot warmers included Wool blend: 19% wool, 49% acrylic, 10% Polyester, 11% nylon, 9% olefin, 2% spandex Medium fits men's US shoe sizes 5-8,Large fits men's US shoe sizes 9-13