(Backordered) Oral-B Braun Oral-B Replacement Brush Heads Precision Clean, 4 PackSpecial X shaped bristles scrub away dirt from small areas that regular bristles can't reach. The green bristles will turn yellow to let you know when it's time to replace them. Maintains maximum plaque removal power (*1). Thoroughly cleans every corner for healthy gums. Oral B genuine replacement brush Can be used with all Oral B round rotary brushes except the iO series. *1 By replacing the brush appropriately, it will return to the same condition