Benefits Features Tuft-in-Tuft bristles-with shorter tufts optimally positioned for surface cleaning and separate, longer tufts for interdental cleaning in hard-to-reach areas. Bristles are precisely angled at 16 degrees to most effectively but Gently sweep away plaque along the gum line. Tufts are engineered in an innovative CrissCross pattern-for ultimate cleaning. On Oral-B's signature round brush head, bristles are meticulously arranged to best surround each tooth for the best possible clean. The only refill brush heads designed exclusively for-and guaranteed to fit-your Oral-B iO. Pack includes 2 refill brush heads.