The Oral-B Floss Action X-Filaments replacement toothbrush head contains clinically proven technologies to deliver a superior clean vs. a regular manual toothbrush. The professionally inspired design of the Floss Action brush head reaches deep in between teeth to remove plaque. Max Clean bristles indicate time to change. The iconic round brush head is inspired by dental professional tools for a tooth-by-tooth clean, with specially engineered bristles. The X-shaped bristles lift, trap, and remove plaque for that all around fresh clean. The Oral-B brush heads are compatible with Oral-B rechargeable toothbrushes, except for Oral-B iO toothbrushes. Always clean thoroughly after use, this does not replace flossing. Do not use on children under age 3. Replace brush (head) every 3 months or sooner if brush head becomes worn.