1. Leading 5000 ml large capacity: Our device offers an impressive maximum capacity of 5000 ml (5 liters), providing a broader range for accurate measurement of lung capacity and contributing to a more comprehensive assessment of lung health. 2. Improve breathing techniques: Practice slow, deep breathing with the device to promote oxygen circulation and expand lung function. 3. Flow rate indicator: Use the indicator to guide your breathing. If the indicator rises to a higher position, it may mean you are inhaling too quickly; if it stays at a lower position, it may indicate you are inhaling too slowly. The goal is to keep the indicator in the middle position, suggesting your breathing is smooth and controlled. 4. Track your progress: Effectively monitor the improvement process of your lung health with the precise measurement function of our device. The large capacity range can provide more accurate and detailed data to assist you in setting and achieving breathing goals. 5. The flexible tube and mouthpiece are relatively easy to adjust and use in different postures and are easy to clean after use. The device has a built - in space to store the tube and mouthpiece. 6. Color: Transparent 7. Material: Plastic 8. Package contents: - 1 breathing trainer Only the above package contents are included, and no other products are included. 9. Precautions: Light reflection and different displays may cause some slight differences between the color of the items in the picture and the actual product. The allowable measurement error is plus or minus 1 - 3 cm.