Outstanding performance without causing excessive leg fatigue Fin angle is 25 degrees to increase comfort and efficiency during the back stroke of the kick Fins parabolic shape displaces more water volume in the midline section of the blade and then tapers down toward the tip to normal width Shaped for thrusting water efficiently during the strongest part of the kicking stroke in a shorter, more agile fin Stiffness: 30/Medium 2 Year Manufacturer Warranty here in USA