Uniquely designed with ultra soft bristles, the Philips Sonicare Sensitive brush head is soft on teeth and gums, yet effective on plaque. The ultra soft bristles combined with a new curved bristle field provide less pressure on teeth and gums to deliver a gentle, yet effective cleaning. The brush head includes reminder bristles that fade from blue to white to let you know when it's time to replace. The American Dental Association recommends replacing your brush head every three months, a fresh brush head maximizes the effectiveness of Philips' unique Sonic Technology. The Philips Sonicare Sensitive Replacement Electric Toothbrush Head is compatible with Philips Sonicare snap on rechargeable handles: DiamondClean, FlexCare, HealthyWhite, 3 Series Gum Health, 2 Series Plaque Control, and Essence+ handles.