Unique hinge design initiates the catch for all swim strokesnAccentuates fingertip flexion upon water entrynMaximizes feel of the waternScalloped edges for smooth pulling action and ControlnThese flexible training paddles are designed to build strength and promote proper technique for a wide variety of strokes. The unique hinge design improves your ability to "catch" the water at the front of the stroke to help boost power and speed. The reduced surface area maximizes your feel of the water, while scalloped edges offer smoother pulling action and incredible control.