Sonic Vibration technology provides effective stain removal. Clinically proven to reduce stains after (2) weeks of use based on university study. Brush efficiency at 31000 brush strokes per minute with sonic technology. Triple-edge bristle brush softly cleans tooth surfaces between teeth and along the gum line. Features two brush modes (white soft) and soft start function. Perfect for home usage on or on the go with travel case and AC Charger. Additional brushes available (WEW0927W)