Gentle yet effective cleaning of sensitive teeth and gums: this toothbrush head features a unique design with long, thin, ultra-soft bristles that keep every brush stroke kind Remove up to 10x more plaque than a manual toothbrush in hard-to-reach areas with more than 3,000 densely packed bristles designed to provide thorough yet gentle brushing Proven Sonicare technology: deep and gentle cleaning with up to 62,000 bristle movements; Sonicare fluid action supports cleaning by driving fluid deep between teeth and along the gumline Click-on design: Philips Sonicare S2 Sensitive brush heads fit all Philips Sonicare handles⁴ You'll know when it's time to change the brush head thanks to BrushSync replacement reminder (compatible handles) that tracks how often and how hard you brush, and when blue bristles turn white 70% of the plastic in this brush head is bio-based²; paper-based recyclable packaging³ The set includes: 4x S2 Sensitive brush heads, black