Portable: Very compact and easy to carry. Adjustable: Features an adjustable resistance dial to make the simplest task more difficult to make workouts more intense. Health and fitness: Get a breathing muscle exerciser. Vital capacity: Helps to expand and improve vital capacity without the risk of having to do a lot of aerobic exercise and burning calories. Endurance: Breathing exercise equipment to challenge yourself for better exercise and improve overall endurance. Breathing Muscle Exerciser | Living Social