PowerBlock dumbbells are the most versatile and effective exercise tool ever developed for strength training. PowerBlocks work intuitively. Rather than requiring you to buy a room full of dumbbells, PowerBlocks act just like a weight stack at the gym, with a weight handle that fits inside the first weight, which fits inside the second, which fits inside the third, etc. When you want to change weights, you simply move the weight selector pin into the appropriate slot and you're set. As you lift the core, all the weights above the selector pin are lifted at the same time, turning your 3-pound dumbbell into a 6-pound dumbbell, or your 6-pound dumbbell into a 12-pound dumbbell. Not only is the system remarkably easy to use, but it's also cost- and space-efficient.

This set adjusts from 5-45 lbs in 5 lb increments (5, 10, 15, 20, 25, 30, 35, 40, 45 lbs) in each hand. This set has a maximum weight of 45 lbs per hand. The Classic 45 replaces 9 pair or 18 fixed dumbbells that would have a combined weight of 450 lbs.