Efficient Propulsion: The short blade is designed to maximize forward thrust while reducing leg fatigue, making them great for long snorkeling sessions or pool workouts. Comfortable Fit: The full foot pocket is made from soft rubber to prevent blisters even when worn barefoot. Hydrodynamic Vents: The visible holes in the blade (as seen in your image) help channel water more efficiently, improving your kicking technique. In good used condition.