Lung Exerciser – Improve Breathing & Lung Capacity - Price: $220

Our breathing muscle gets stronger. Its light, yet tough plastic construction makes it lightweight and convenient for carrying and handling, so you can use it anywhere at home, in the clinic, or when you're traveling. Lung Exerciser – 3-Ball Spirometer! Perfect for recovery after surgery, respiratory therapy, exercise training, or general lung care, this portable device assists you in building stronger breathing muscles and tracking lung capacity in an easy, handheld manner.
For more info: https://www.gstc.com/product/lung-exerciser/