Sporasub Spitfire Kelp Blue freediving fins with foot pockets made from thermo-rubber with two different hardness in order to combine the best in comfort and performance. The blue parts have a stiffness of just 40sh, offering a soft and comfortable contact with the ankle and toes. The black parts have a stiffness of 90sh, able to transmit power without dispersion. The Spitfire features anti slip patterns on the heel. The detachable blade has 2 water rails to eliminate skidding and greatly improve performance.