Sonicare's Diamond Clean brush heads delivers the ideal plaque removal performance, removing up to 100% more plaque than a manual toothbrush. The black brush heads are designed to complement DiamondClean Black toothbrush, and four are provided in the pack. Diamond-shaped bristles provide a greater surface area for an exceptional cleaning and whiter teeth in just one week. The diamond bristle heads have 44 per cent more bristles than Philips Sonicare's standard sized ProResults, providing you with both plaque removal and whiter teeth. The bristles are medium stiff, delivering a firm yet gentle cleaning experience, and the bristles gently fade in use to remind you when the brush head needs to be replaced.