Tough on plaque. Gentle on gums. Removes up to 7x more than a manual toothbrush. The Philips Sonicare C2 Optimal Plaque Defense toothbrush head is perfect for tho. Features densely-packed, high-quality tufts to effectively remove plaque. Fits any Philips Sonicare click on toothbrush, simply click off for easy replacement. When used with a compatible BrushSync enabled Sonicare toothbrush our smart brush head replacement reminders will alert you when the brush head needs replacing for effective cleaning, every time. All genuine Philips Sonicare brush heads are safe and gentle on teeth and gums. During tests, our brush heads are put through their paces to ensure you get exceptional performance and durability each time you brush.