The Oral-B iO gentle cleaning replacement brush heads combine powerful yet gentle micro-vibrations with a unique, dentist-inspired round brush head for a professional cleaning feel every day. Exclusively designed for Oral-B iO electric toothbrushes, these gentle cleaning brush heads help remove up to 100% more plaque than a traditional manual toothbrush, leaving teeth looking clean and bright. The gentle cleaning brush head features 4,000 soft bristles and a cushioning outer ring to adapt perfectly to the contours of the teeth and protect the gums. Since dentists recommend replacing the brush head every 3 months for optimal results, Oral-B replacement brush heads come with color-changing bristles that signal when it's time for a change. Experience superior cleaning power with the only replacement brush heads specifically designed and guaranteed to fit the Oral-B iO electric toothbrush.