The only dumbbell system that can expand to meet your strength needs, these dumbbells are the most versatile and effective exercise tool ever developed for strength training. It works intuitively. Rather than requiring you to buy a room full of dumbbells, acts 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, as a single pair of dumbbells can do the work of dozens.