This is a portable handheld spirometer that measures your ability to exhale air from your lungs and provides accurate airway ventilation images.It is very suitable for athletes, people who need oxygen and have asthma.Double flow range accurate measurement, real-time reading tracking airflow changes to detect asthma problems.Made of high quality materials, durable.Accurate measurement of peak respiratory flow is helpful for early detection of asthma attack. Our products are made with the highest quality materials and are designed to provide you with the best possible user experience. We strive to ship out all orders within three days of purchase, and the estimated delivery time is 8-15 days. When shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specifications We want you to be completely satisfied with your purchase, so if you have any questions or concerns, please don't hesitate to contact us. We are here to help and will do our best to assist you. Thank you for choosing our product. We hope you enjoy it!