mattWill Flexible One Size Womens Casual Cotton No-Show Low-Cut Sock Liners with Anti-Slip Grip Box Set (Pack of 6) Material: Bamboo Fiber & Cotton Uniquely designed with a silicone finish at the heel to hug your feet & not slip off Designed to be truly hidden to the visible eye in a high-heel shoe, ballet flats, or sneakers Size : Based on US Shoes Sizes (Heel to Toe). Machine Wash Or Hand Wash Recommended.