The Oral-B Pro Precision Clean toothbrush head bristles brush away plaque for a superior tooth-by-tooth clean than with a regular manual toothbrush. Oral-B genuine brush heads are designed with new X-shape bristles that clean in areas that round ones cannot reach. Its brush head usage indicator turns bristles from green to yellow showing you when to change for 100% cleaning efficacy. Guaranteed fit with Oral-B electric rechargeable toothbrushes except Pulsonic & iO toothbrushes. Dentists recommend replacing your toothbrush head about every 3-4 months, or when bristles are faded and worn. Each brush head hygienically sealed for convenient storage.