8- PACK REPLACEMENT BRUSH HEADS for PURSONIC S/400 /S450 /S600 models.High quality Dupont Tynex bristles. Innovative wave bristle design for deep and complete cleansing.Promotes ultimate plaque removal.Dental professionals recommend changing your brush heads after every 3 months of use to maintain healthier teeth and gums. Dimensions:. Length: 8. Heigth: 4. Width: 0.5