I made an incentive spirometer which is used to maintain and improve the function of the lungs. In space the chamber will be printed in transparent plastic to see the components of the incentive spirometer and the purple mouthpiece will be printed in flexible plastic. The way it works is when you inhale and take a deep breath in from the purple mouthpiece, the force of your breath will be transmitted from the mouthpiece and through the connecting tube to the top of the main chamber. This will then rotate the flippers up on their orange hinges and then raise the green ball. The longer and harder you inhale, the higher the ball goes. The resistance provided by the connecting tube, flippers, and ball will help strengthen lung function. Doing this repeatedly in a micro or zero gravity environment such as on Mars will maintain and even improve the function of your lungs.