The Weider Speedweight Adjustable Dumbbell Set helps you define and strengthen your muscles. The Speed Pac weights work just like a weight stack at the gym. When changing weights, simply move the selector pin to the desired weight range. The storage tray includes a color-coded weight guide to refer to. Each Speed Pac weight varies from 2 to 12.5 pounds - in 2.5 pound increments. Cushioned for comfort, they're easy to use and produce amazing results.