Typhoon Vortex 5mm Round Toe Boot The Typhoon Vortex 5mm boots combine quality, durability and warmth alongside excellent value for money. Perfect choice for year-round use and for virtually any watersports activity where warmth and flexibility are required.   Features 5mm double lined Neoprene Glued and blindstitched seams Flexible pull-on Neoprene boot with longer ankle/calf seal for improved warmth Lightweight sole providing superb flexibility and grip Rubber reinforced achilles and ankle support and toe protection Toe Flex cut-outs and arch for support and enhanced flexibility