The Arena Powerfin Pro II is an eye-catching and effective training tool for competitive swimmers. Designed for power training and leg technique, these fins are designed with a short blade for maximum forward thrust and an open heel for maximum ankle flexibility, stability and comfort. The special notches on the bottom ribs help kick faster, while the side grooves ensure better control. Left and right fins are shaped individually. The soft silicone is comfortable to wear and reduces your chance of getting blisters. PVC free.