These awesome NASA sock liners go perfect with everything. No slip heel tab keeps the liner in place to prevent that annoying bunching some liners cause. Great style for those NASA fans. Elastic arch provides great support in this athletic liner. You get two great designs in this two pack of sock liners. Size SM fits men's shoe sizes 5-8, women's shoe sizes 5-10 and kids shoe sizes 5-8, while the LXL size fits men's shoe sizes 8-12. Please note: Socks are not able to be returned or refunded if they have been removed from their original packaging.