Akona 3.5mm Standard Nylon Rubber Sole Side Zip Boot 3.5mm nylon II neoprene utilizes glue and blind stitched seams for a superior water seal. New design provides a contoured and snug fit, creating a more comfortable and warmer boot. SOLE: The new improved AKONA boot sole provides exceptional "no-slip" grip texture. This new spike-like rubber sole features a deep cut pointed texture that drastically reduces hydroplaning across a boat deck, dock, sidewalk or floor. 30% thicker than the average vulcanized rubber sole, AKONA s new sole design provides comfort, stability and confidence while being worn before, during and after the dive. ZIPPER: YKK #5 self-locking and corrosion resistant zippers. Full-length zipper pocket minimizes water entry. A longer pull-tab on the heel allows you to don the boot with greater ease.