The SpaBells Aquatic Exercise System is designed to take full advantage of water as a total body exercise medium. These are adjustable dumbbells that harness the power of water resistance to tone muscles, burn calories, and enable full-body water workouts without the strain and injury of training above ground. The two included dumbbells have funnels and two sets of fins that allow you to adjust resistance as you perform curls, chest flies, or shoulder raises. An additional set of fins can be attached to the dumbbells to help in building muscles and strength. The included caps trap air inside the dumbbells and seal the funnel, making them buoyant and allowing users to workout on the water surface by running in place or performing scissor kicks to tone legs. The funnel caps can also be used to trap water inside the dumbbells, creating two 8-lb. dumbbells. The dumbbells also attach to each other to form a barbell for performing chest presses or front raises.