The Philips C3 Premium Plaque Defence adapts to the contours of your teeth and gums thanks to soft, flexing sides that give you 4 x more surface contact than a regular brush head for a comfortable, deep clean. 4-pack. Standard size. Click-on. BrushSync mode pairing. Thanks to its flexible design, it removes up to 10x more plaque from hard-to-reach areas for a truly deep clean along the gum line and between teeth.