The Philips Sonicare HX6058/88 replacement brush heads are designed for adults who need a gentler touch for sensitive teeth and gums. These black, oval-shaped heads feature over 3,000 densely packed extra-soft bristles that work with Sonicare Fluid Action technology to drive fluid deep between your teeth and along the gumline. By utilizing this sonic movement, these heads can remove up to 10 times more plaque than a traditional manual toothbrush. This pack includes eight brush heads, each marked with 'S2' on the neck for easy identification, ensuring you have a steady supply of replacements for your compatible Philips Sonicare handles, though they are not intended for use with Philips One models.