Work out in the water and tone and strengthen legs and lower back, inner and outer thighs, arms, chest and upper back One-size-fits-all cuffs and Predator Fins are made of soft Santoprene rubber for strength and flexibly and can be worn comfortably on the wrists or ankles for full body conditioning Drag resistance is adjusted by rotating the fins Helps with discomfort or use following hip replacement or knee replacement to increase endurance and strength Each kit contains 2 cuffs, 4 Predator Fins, a mesh carrying case and detailed instructions