These innovative footpocket insoles are designed & manufactured by C4, in order to make your fins more powerful, more snug, and more fun. Their anatomic shape increases comfort, minimizes air spaces, and forms left/right foot shapes, for an immersive freediving experience. They effortlessly improve the planar shape of the footpockets under the foot arch, eliminating the void, increasing the control of kicking, and optimizing the force transmission, making everything efficient, smooth, and easy. Dive more comfortably in colder waters, as the reduction of the air space inside the footpocket restricts the flow of water, thus keeping your feet warmer.