INCREASE MUSCLE ENDURANCE : Use muscle trainer to Boost stamina in respiratory muscles and improve breathing ability. Also dilate diaphragm. Strengthen your respiratory and abdominal muscles with professional breathing training to ultimately improve your athletic performance. EXCELLENT EQUIPMENT : Portable and light,soft silicone,easy to clean and adjustable resistance Settings-which can provide a personalized experience OPERATION INSTRUCTION: Take exhalation and inhalation as a set of 10 to 15 times of exercises, do 2 to 4 sets of simple breathing exercises per day. Adjust the appropriate resistance, keep training then you will feel the increased endurance of your breathing muscles. ESSENTIAL FOR EXERCISE: It is must for exercise lovers, the breathing trainer is suitable for high-energy training sports such as walking, running, swimming, cycling, martial arts and outdoor activities. Improve your respiratory endurance for optimal athletic performance. MEET YOUR EXPECTATIONS : Keep using the Respiratory Trainer and you will feel the change in regular use. With better Exercise Device and better functional support. This is a good lung trainer in your training program.