These are the fins all swimmers have been waiting for. Their innovative design features a sloping surface and hydrodynamic slits in the top to allow you to swim with a faster leg kick and better control. The open heel ensures the best possible ankle flexibility allowing faster upwards motion and a more powerful downward leg kick. Training your legs vertically using Powerfin Pros for just a few minutes today will help you improve your underwater phase. The vertical leg kick allows you both to control your body position and make sure you are performing a proper leg kick. Features Inclined short blade for maximum forward thrust and high frequency kick Special notches on the bottom ribs for faster kicks and side rails for better control Customized for left and right foot, with open heels for maximum flexibility