Brooks Nightlife Quarter Sock, 1-Pair Pack Dri-Stitch Nylon 96% Dri-Stitch Nylon, 4% Lycra Arch compression helps prevent socks from sliding into the shoe during physical activity. Size is knit into the sock for quick identification. A flat toe seam all but eliminates the chance of blisters caused by friction between harsh seams and toes Machine Washable, Tumble Dry on Low, non-chlorine bleach as needed USA