Powerblocks are one of our favorite products we sell. They're incredibly efficient in terms of both cost and space -- especially when compared to a full rack of Dumbbells.
The Sport EXP series is adjustable from 5 to 50, 70, or 90 lbs. You can also start with any "Stage" you want, and then upgrade later to a higher weight class when you buy any EXP Series for $129 per upgrade.
The Sport series of Powerblocks are a coated steel. For a rubber-coated version, be sure to check out the Pro EXPs we also stock.