The io 4 electric toothbrush features oral b's best technology, combining a dentist inspired round brush head with micro vibrating bristles for a professional purifying clean feel at home'. '.strtoupper('t')he smart pressure sensor helps prevent you from brushing either too hard or too softly to better protect your gums'. '.strtoupper('g')um guard alerts you to time spent brushing with too much pressure'. '.strtoupper('r')eplace your oral b io toothbrush head every 3 months for the best results'. '.strtoupper('f')or healthier gums in just 1 week with oral b's most advanced technology removes 100% more plaque and up to 160% in between teeth vs'. '.strtoupper('a') manual toothbrush track and improve your brushing habits over time with the oral b app through performance reports, journeys, and goals protect your gums with the io pressure sensor oral b's only sensor to signal if you brush too hard, too soft or just right for an effective and safe clean personalise your brushing choosing among 4 cleaning modes daily clean sensitive super sensitive whitening always maximise your clean with the io lightring timer that celebrates a dentist recommended 2 minute brush and refill change alert oral b round brush heads reach where rectangular manual toothbrushes don't'. '.strtoupper('e')xperience a better clean from the 1 brand most used by dentists worldwide benefit from a long lasting charge with the lithium ion battery