Check the listing for details. Breathing Trainer Lung Exerciser with Flow Indicator. Condition: New, Made in China. Listed at 29.94 USD. BREATHING TRAINING: Use our lung trainer to improve your breathing, which is a multifunctional breathing trainer designed for practicing slow and deep breathing. Easily improve traffic and expansion.Incentive Spirometer Adult. PRECISION GUIDANCE WITH INDICATORS: Flow Rate Indicator guides your breathing pace.Let the indicators be your breath companion.Keep the indicator within the middle range for steady and controlled breaths. 5000 ML VOLUME: Our equipment provides a maximum capacity of 5000 ml (5 liters), which provides a wider range for accurate vital capacity. HIGH QUALITY MATERIALS: The deep breathing trainer is made of high-quality, drop-resistant plastic, with a compact structure for measuring and deep breathing training system.