The 1PCS Lung Trainer Breathing Trainer is a portable and easy-to-use device designed for adult fitness enthusiasts. Made of silicone and plastic, this black trainer is adjustable to meet different fitness needs makes it convenient to store and transport, while its indoor and outdoor capabilities allow for versatile use. Perfect for improving lung capacity and overall fitness, this breathing trainer is a must-have for anyone looking to enhance their performance in activities like running. Great anyone trying to improve lung strength  and capacity  free shipping