Description:1. BREATHING EXERCISE: Breathing exercise device challenges yourself to perform the better workout and improvement of your overall stamina.2. LUNG CAPACITY: It helps to expand and improve your lung capacity without having to do a ton of cardio and risk burning calories.3. PORTABLE DEVICE: Lung breathing trainer is extremely compact. With this device, perform your daily training wherever you are.4. WORKS GREAT: Adjustable resistance dial makes simplest tasks tougher and workouts more intense as your needs.How to use a lung exerciser1. The user breathes through a breathing training device.2. When exhaling, use the force of the diaphragm to inhale and expel the air.3. Find a resistance that allows you to inhale by yourself while exhaling.4. Repeat a few times and then rest.5. Repeat 4-5 times a week.Specification:Material: Silicone, ABSSize: 5 x 10 cmApplication: swimming training; running, cycling, etc.Package Included: 1 x Lung Exerciser