4 or 6-Pack: Replacement e-Series-Compatible Toothbrush HeadsThe e Series Compatible Toothbrush Heads are visibly angled for better reach within the mouth, providing a thorough every day clean, while massaging and stimulating gums. Features: FDA approved Compatible with Philips Sonicare Advance, Elite, Essence, and Xtreme series handles Fits the natural shape of your teeth for a thorough clean Bristles have reminder marks that fade when they need to be replaced Made to remove two times the amount of plaque than