Our Patented Dual Dial Adjustment Handles have Two Dials for multiple reasons; 1. It allows our users to select different weights on each side of the handle. If you haven't tried "Offset" Training before, it can add incredible variety to your workouts. Simply add a couple extra plates to one side of the dumbbell handle for pressing, bicep and shoulder movements. Start light and see where "Offset" training can help your workouts.  2. Our Mechanisms are designed with 100% metal gears and shafts, we do NOT use small wires, plastic gears, or little plastic tabs. Our Design requires the use to use of a dial on each end of our dumbbell handle to accurately select your desired weight.