AGPTEK 16x PCS 4 Generic Oral B Compatible Toothbrush Replacement Heads EB-18A Polishing cup: Holds toothpaste to gently remove surface stains to naturally whiten teeth Outer bristles: Surround each tooth to clean thoroughly Indicator bristles: Fade halfway, to signal when to replace your brush head Gently removes surface stains to naturally whiten teeth Cleans thoroughly