Compatible with Oral-B iO toothbrushes only Revolutionary iO technology right down to the bristle tips The padding effect of the outer bristles protects the gums and ensures a pleasant mouth feeling The bristles of the unique, round brush head surround each tooth individually For the best cleaning, dentists recommend changing the brush head every 3 months. Oral-B is the No. 1 toothbrush brand, which is most commonly recommended by dentists worldwide. Box contents: 4 Oral-B iO gentle cleaning brush heads (individually packed for hygienic reasons)