85% Cotton. 13.5% Polyester. 1.5% SpandexMachine WashNO SLIDE OFF:Unique silicone design. close to the heel to prevent falling off.(In picture.5 socks means 5 pairs of no show socks.10 socks means 10 pairs of the item)LOW CUT SOCKS : almost completely hidden inside for many shoes.PACKAGE CONTENTS:5/10 pairs(10/20 socks) assorted in Pareberry pack.THICK CUSHION SOCKS:It can effectively prevent the top of the sock from being broken and the material is very comfortable.SOFT and WARM:We select high quality cotton.They are very soft.breathable and comfortable.SIZE:Medium = Women's Shoe Size(5-8.5) OR Large = Women's Shoe Size(9-11.5).