Features:1. The breathing exerciser is made of high-quality silicone material, which is harmless to the human body, safe and reliable, and can be used with confidence. 2. Breathing exercise equipment to challenge yourself for better exercise and improve overall endurance.3. Vital capacity: It helps to expand and improve vital capacity without the risk of having to do a lot of aerobic exercise and burning calories.4. The portable device: The lung breathing training instrument is very compact. Easy to carry.5. The adjustable resistance dial makes the simplest task more difficult, and can exercise more intensely according to your needs. Notice:1.Actual color may be slightly different from the image due to different monitor and light effect2.Please allow 1-3cm deviation due to manual measurementDescription:Material: SiliconeSize: As shownincludes:1 x Breathing Trainer