The Mutant 6/5/4 IST Bootie from O\'Neill is a flexible and warm surf bootie. You want warm feet on your cold water trips? Then the Mutant Bootie is your friend. The booties have glued blind stitch seams that prevent water from entering. Also, your toes are split for greater freedom of movement. A rear loop helps you to put on the bootie very easily. Features6/5/4 mmBonded blind stitch constructionLoop for better tighteningFluidFlex FirewallUltralight Foxing Support SystemInner split toeInner welded seam