The AEROCHAMBER PLUS FLOW-VU Chamber is the only chamber with a dedicated inhalation indicator. The FLOW-VU Inhalation Indicator is a valuable feedback tool on the AEROCHAMBER PLUS FLOW-VU Chamber that moves as the user breathes to confirm correct use and medication delivery. The FLOW-VU Indicator is especially useful for parents who are giving the inhaler medicine to their children. The indicator lets you count the number of breaths your child takes through the chamber and helps you to know the medication was given correctly.