The soft, breathable 100% nylon mesh is made of interwoven material keeps feet cool and fresh. The low cut design is nearly invisible in shoes to provide discreet coverage for all day comfort. The non-binding elastic edge holds both feet snugly in place ― stretchable to fit most women's sizes between 4 to 9. The additional anti-slip silicon beads on sole prevents slipping! Free Size, Suitable for Uk 4 to 9 feet.