Braun Oral B iO Series 9 Electric Toothbrush Black Onyx combines powerful, but gentle micro-vibrations with Oral-B's unique dentist-inspired round brush head design for a professional clean feeling every day. The smart pressure sensor helps to keep you from brushing too hard to protect your gums and enamel. 3D teeth tracking and Al recognition use an interactive color display to help guide you to your best clean for all areas of the mouth. A 2-minute quadrant timer comes built in that pulsates every 30 seconds, ensuring a complete clean. The frictionless, smooth magnetic drive system transfers energy to the bristle tips for a clean that wows. Replace your Oral-B iO Series replacement brush heads every 3 months for best results.