Bowflex SelectTech 552 Adjustable Dumbbells

The 552 Adjustable Dumbbells allow you to pack a variety of weights into the same space where you would otherwise stash just one. These durable weights easily change from 5 to 52.5 pounds each, so you can go lighter or heavier with the turn of a dial. We especially liked how the adjustments are made in small, 2.5-pound increments, so you can safely and gradually increase the load. [$349; bowflexselecttech.com]