3.Multi-level bristles to aid thorough cleaning, medium strength rounded-bristles to be soft on gums;
4.Compatible with DiamondClean, FlexCare, FlexCare+, FlexCare Platinum, EasyClean, HealthyWhite, 3 Series Gum Health, HydroClean Sonicare 2 Series Plaque Control and Sensitive Toothbrush Brush Handles;
5.Philips recommends replacing your brush head every 3 months for optimal results.