High Compatibility : Trustnice brush heads are specifically designed to fit Oral-B iO toothbrushes, Brush Heads Compatible with Oral b IO 3/4/5/6/7/8/9/10 Electric Toothbrush. Effective Clean: The design with long and short bristles allows the Trustnice precision brush heads to enclose the teeth and penetrate deep into the interdental spaces, removing 5X more plaque along the gum line than with a manual toothbrush.