SPEEDO Aqua Fit 360? System * Multi-directional dumbbell set allows you to customize the intensity of your workout by varying levels of buoyancy and resistance tailored to fit your own individual fitness level. * Interchangeable resistance discs promote water flow in a desired direction. * Exclusive slide-and-lock system lets you easily change components. * Removable foam weights promote variable buoyancy. * Soft padded grips and straps reduce stress on joints. * Add both foam weights and resistance discs for complete underwater toning. * Additional Foam Attachments sold separately for increased resistanceSee Style #7530358.