Soft and pliable Kiefer Silicone Swim Training Fins are extremely durable in the pool and offer a very comfortable fit. They are the perfect swim training tool for kicking drills and swimming sets. Short blade fin design improves kick strength and ankle flexibility, causing development of proper flutter kick technique. Swim fins are color coded for quick and easy sorting for swim teams and aquatics programs. When swimming without them, you'll notice an improved strength and efficiency. Kiefer - The First Name in U.S. Swimming since 1947.