Size Indication: Sizes displayed are in US sizing Material Composition: Body made of 1.5MM 80% Neoprene/20% Nylon Footbed Flexibility: 0.5MM Rubber in footbed for optimal flexibility Design Philosophy: Ergonomic design for supreme durability and protection Footbed Reinforcement: 1MM Rubber in critical areas of footbed Ankle Support: Adjustable velcro strap for secure lockdown Designed ergonomically for supreme durability and protection.