Heat Factory Acrylic Blend Socks w/Foot Warmer Pockets, 2 Pairs Twopairs of acrylic blend socks with Mossy Oak pocket sewn in above the toe, holds disposable Heat Factory foot warmer Socks constructed with cushioned arch and reinforced heel; above-calf length One pair of Heat Factory 6+ hour foot warmers included 93% acrylic, 7% polyester Medium fits men's US shoe sizes 5-8,Large fits men's US shoe sizes 9-13