The electric toothbrush iO 4 is equipped with Oral-B technology and combines a dentist-inspired round brush head with oscillating bristles for a professional cleaning experience at home. The smart pressure sensor helps you avoid brushing too hard or too softly, better protecting your gums. The gum protection feature alerts you when you brush for too long with too much pressure. Replace the Oral-B iO toothbrush head every 3 months for optimal results.