Volume measurement designed to accommodate large, inspired volumes. Particulate filter screen in device housing helps reduce risk of foreign matter passing to patients. Flow indicator with smiley face provides visual target for desired inhalation and bright green flow indicator make it easy for patients to see results. Ergonomic swiveled mouthpiece allows to patients create tight seal to enable more accurate measurement. Latex free Expandable and collapsible tube helps patients find comfortable position for treatments and can be removed when storing the device.