Replacement brush head for Sonicare electric toothbrush. Best brush head for an ultimate clean. Suitable for these models: FlexCare+, FlexCare, HealthyWhite, HydroClean, EasyClean, DiamondClean. Medium stiff bristles provide a firm, but gentle experience. Reminder bristles let you know when to replace the brush head. After three months of normal use bristles exhibit fatigue, and brush heads are less effective. Replace your brush head every 3 months.