This is the Tusa Hyflex Vesna Open Heel Fins for Scuba Diving and Snorkeling Features: Powered by APS Active Pivoting System" Newly designed "Comfort Foot Pocket" enhances performance Multi-compound foot pocket increases power transfer to the fin blade Blade vent maximizes propulsion by reducing water resistance and turbulence Reinforced blade rails and a flexible blade pocket moves a large volume of water "NEW" TUSA Reflective material keeps you visible in low light or at night Color: Black (BK), Cobalt Blue (CBL), Fishtail Blue (FB), Flash Yellow (FY), Hot Pink (HP), Metallic Red (MDR) Sizes: XS, S, M, L The SF0101 TUSA Hyflex Vesna combines TUSA&';s unique fin design with the latest advanced materials and hydrodynamic innovations. TUSA Hyflex Vesna is powered by TUSA&';s unique APS "Active Pivoting System" technology, the combination of uniquely positioned holes that reduces drag while maintaining constant propulsion. With a newly designed multi-compound "Comfort Foot Pocket", the Hyflex Vesna has several unique features that deliver superior performance and power transfer to the fin blade. TUSA Hyflex Vesna features new TUSA Direct Reflect technology with advanced reflective material to keep you visible in low light or at night.