You can't judge the difficulty of lifting the Power Dumbbell based on the way that it looks, for this single piece of exercise equipment can actually change its mass. You would no longer need an extensive collection of free weights in your home gym, or even to visit the fitness center, for you're completely stocked up with just one set.
Jun Young Choo's invention relies on the principle of the gyroscope with spinning internal elements that increase in centrifugal force with their speed. Making an adjustment this way enables you to change the way that the weights feel in your hands, seemingly becoming heavier and bringing more intensity to your bicep curls. The Power Dumbbell even has a display screen on the end to indicate the weight and the calories you're burning.