Incentive spirometers are used to help wind and brass players improve their breathing. The breathing exercises are designed to help players take long deep breaths, similar to a yawn. Deep breathing leads to more efficient playing and helps improve phrasing and tone. A one-way valve ensures users inhale, rather than exhale into the unit. The Coach 2 has highly visible pistons to help users perform and monitor their breathing exercises without direct supervision. It's a real medical device, and includes a unit and flexible breathing tube. This unit functions similarly to the Voldyne (037940) except that it has 40% the measurement capacity (2.0 liters as opposed to 5 liters for the Voldyne). Features: