One great feature of these PowerBlocks is that once you're ready to move beyond 50 pounds, you don't have to go out and buy an entirely new set of adjustable dumbbells. The expansion kits allow you to ...

You can purchase them in pairs, which range from 10 pounds to 100 pounds, or as sets of 10 dumbbells with multiple weight options that go up in increments of five pounds, including a 5-pound to 55 ...