A three-ball lung exerciser, also known as a spirometer or respiratory exerciser, is a medical device used to improve lung function and promote respiratory health. It is designed to help patients with respiratory conditions, such as asthma, chronic obstructive pulmonary disease (COPD), or postoperative patients, to strengthen their respiratory muscles and expand their lung capacity. The main features and components of a three-ball lung exerciser include: Three Balls: The lung exerciser consists of three colored balls of different sizes housed within a clear plastic chamber. Each ball corresponds to a specific level of inhalation effort and indicates the amount of air being inspired by the patient.