Vital capacity (VC) refers to the total amount of gas that can be exhaled at a time when you try to breathe in. Adult men"s vital capacity is about 3500-4000 milliliters, and women are about 2500-3000 milliliters. The better the health is, the greater the vital capacity is. Spirometer is a portable, handheld device for measuring your ability to exhalate air from the lungs, and can provide a correct data to reflect the ventilation of the trachea. The importance of vital capacity: The vital capacity of the lung is closely related to the human respiration. Physiological studies show that the organs, systems, tissues, and organs of the human body Spirometry (low values compared with normal values), indicating that the body oxygen uptake and exhaust, the oxygen supply inside the body is not sufficient, once the body needs a lot of oxygen consumption situation (such as long time learning, work, strenuous exercise) there will be a serious shortage of oxygen supply, resulting in adverse reactions such as headache, dizziness, chest tightness, listlessness, inattention, memory loss, insomnia, this will not only affect the learning and work, and will cause many irreparable losses to health. Usage method: 1. move the red movable buoy to the starting point. 2. use the mouth to hold the blue mouth, breathe deeply, hold the breath, blow out a breath, and try to blow the buoy farther. 3.observe the location scale of floating buoys. The average adult men can reach 400L/min, the females can reach 350L/min, and athletes and vital capacity can reach 600-700L/min. (routinely calculated by milliliter ml. This lung activity meter is measured by ascending L. The conversion is as follows: if the scale you measure is 400L/min, the conversion to regular units is 4000ml/min. How to use the peak flow meter? Dial the red pointer to the starting point of the ruler, and the fingers of the peak current meter do not interfere with the activity of the pointer. Stand up and breathe deeply. The peak flow meter mouthparts into the mouth, lips tightly wrapped with mouthparts, forced a quick breath. Write down the value of the red pointer and dial the pointer to the starting point Repeat the above action three times in a row and take the best value. One should pay attention to is: with the greatest strength and the fastest speed to exhale; lips tightly wrap the mouthparts, can not leak; don"t block the hole with the tongue, mouth parts. If you want to repeat the test, please note that the red cursor pointer should be dialed to the lowest point of the scale before each test. Package include:1Pc Spirometer(Adult or child,Color random) 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!