CareFusion AirLife™ Volumetric Incentive Spirometers without 1-way valve 4000mL Capacity The AirLife™ Air x™ flow incentive spirometer is disposable and designed for exercising and measurement of volume ?ow. Preoperative and postoperative patients increase their lung volume by keeping the instrument's inhalation-sensitive ball suspended with their inhalation. The flow passages vary in diameter, affecting the effort required to raise the ball. The ball stays suspended as long as the patient maintains this effort. The flow indicator dial can be adjusted to indicate flowrates in mL/second. Includes spirometer housing, detachable base plate, 12" segmented corrugated tubing with 22mm O.D. and mouthpiece.