Deep Breathing Lung Exerciser - This breathing exerciser is very easy to use. Blow directly at the mouth of the tube to move the ball as higher as you can. Anyone can use it easily. ( If you feel lightheaded or dizzy, stop the exercise and rest first.) Breathing Trainer - This breathing trainer will help to fight stress and anxiety. When you inhale deeply, it clears your mind as well, getting rid of stress and anxiety caused by daily routine and activities. Clear Defferent Levels Indicator Faces - The appearance design of the lung function respiratory exerciser, smile/sad face corresponds to different vital capacity, which can quickly understand your vital capacity, which is very convenient. Safe & Environmentally - The measuring training instrument is made of high-quality PVC plastic material, environmental protection and safety, will not harm or impact on the human body. Portable and Easy to Clean - Compact size, and ergonomic handle for easy grip while in use. The breathing tube is adjustable, you can place it in the handle when not use. Save space, it is very easy to store and carry. You can use it at home, office. Easy to stow in your bag and bring wherever you go.