The iO is Oral-B’s best technology: Clinically Proven 400% More Plaque Removal Along Gumline versus a regular manual toothbrush. A Round head and gentle micro-vibrations, the Magnetic interaction delivers smooth, harmonious motion through a Synchronized cleaning action (micro-vibrations synced with oscillations). A Built-in-2-Minute Timer ensures an even easier experience, helping you get an optimal clean on all your teeth. The Oral-B's quadrant timer breaks the two minutes up into four 30-second intervals to clean each quadrant of your mouth; we keep the time, so you don’t have to. Delivering the perfect pressure is done by having a Pressure Sensor.