medical grade silicone Imported PORTABLE & EASY TO USE -- breathing trainer is extremely compact. It ideal for carrying in your pocket, purse, backpack, or car. And it also has a hanging lanyard. With this device, perform your daily training wherever you are. The breathing trainer helps to improve breathing muscle strength, stamina, and reducing breathlessness ADJUSTABLE RESISTANCE -- 10 levels of adjustable impedance training stages, by adjusting the number of resistance to enhance the training impedance progressively to enhance the effect of breathing muscles. Breathe Better for Improved Health. Our breathing exercise device is the simple, safe, and effective solution to help improve quality of life SIMPLE & SAFE -- Simply use for 30 breaths twice daily to increase the strength, endurance, and fitness of your inspiratory muscles. Our breathing device works by creating a resistance when you breathe in. This strengthens your breathing muscles by making them work harder. (It is equipped with 5 filter pads, so you can replace them according to your needs.) DRUG-FREE SOLUTION -- Regular use of breathing trainer can help to expel harmful pollutants and impurities that have built up in your airways. It means you can breathe easier and enjoy a better quality of life, all without the side effects of drugs. FEATURE: medical grade silicone make it safe and durable. It can be dismantled for washing, cleaning and disinfection. This makes a thoughtful gift for anyone who wants stronger lungs.