Replacement Heads "Compatible With" Oral B IO Electric Toothbrush,Toothbrush Brush Heads Compatible With" IO 3/4/5/6/7/8/9 Series, 4 Count Plaque Control (Black, Standard){Inchcolor_nameinch:InchBlackinch,Inchsize_nameinch:Inch4Count(Packof1)Inch}