Your Sonicare brush head and handle are the ultimate team. The ProtectiveClean 4100 is a gentle power toothbrush with a pressure sensor that protects teeth and gums from excess brushing pressure. The snap-on Optimal Plaque Control brush head features densely-packed high-quality bristles that gives you extra gentle brushing removing up to 7x more plaque vs. a manual power toothbrush. Brush heads wear out over time. Our BrushSync technology tracks how long you have been using your brush head and how hard you have been brushing. It will beep to inform you when to replace your brush head. The easy-start feature slowly increases the power of the brush as you get used to the Sonicare experience and the smartimer encourages a full 2 minutes brushing time as recommended by your dental professional. The battery charge indicator light lets you know when it is time recharge; 2 week battery life. The kit includes 1 Philips Sonicare ProtectiveClean 4100 electric toothbrush, 1 Optimal Plaque Control brush head and 1 charger.