New AERIS Velocity X3 Open Heel Scuba Diving & Snorkeling Fins with Spring Heel Strap- Yellow (Size X-Large/2X-Large-12+) Includes Spring Heel Strap for streamlined comfort and easy on and off Patented Nature's Wing Propeller Fin Technology Power Enhancing Vents accelerate water over the blade for increased velocity Oversized side rails add rigidity for increased lift, power, and efficiency Ergonomically designed foot pocket accommodates virtually all foot sizes and boot styles