This is the Zeagle Recon Fins Tech Diving Open Heel Scuba Diving Fin Features: Advanced performance features integrated with an uncomplicated design for optimal thrust and response. Maximum thrust in flutter, and stability in alternative kick strokes with the latest aerodynamic technology. Tough and durable natural rubber defies the elements Adjustable, quick fastening stainless steel buckle system. Generous foot pockets fit all sizes of wetsuit and drysuit boots. 25 degree angle between blade and foot pocket tried and tested to optimize thrust Two thick side rails provide snapback and flex where it's needed Integrated foot pocket rails efficient energy transfer from foot to fin for responsiveness Built from compression molded rubber for rigidity and suppleness where it's needed Negatively Buoyant RECON is a revolutionary technical fin that's a total rethink of basic fin geometry, angles, surfaces and thicknesses, combining uncomplicated design with the latest aquadynamic technology. It's developed and tested for optimal responsiveness, and provides stability for technical dives and alternative kicking styles, like frog kick and helicopter turns. Aerodynamic surfaces, four strategic strakes on the top and underside, and thick side ribs combine to generate optimal thrust and performance across the entire fin. Available with color accent kits for buckle and soft pad, and the Zeagle Multi-Tool for adjustments on the fly. "