Bas Rutten, Official O2 Respirator Breathing Lung Trainer TRAIN YOUR LUNGS: Revolutionary design by Bas Rutten BENEFIT FROM: Increased concentration of red blood cells and decreased maximum cardiac output PROVEN TO WORK: All of the participants in our test increased their ventilator muscles and improved the volume of air they could ventilate VERSATILE DESIGN: 10 different sized caps for training at different levels SAFE TO USE: Compact, convienent, safe for you and for the environment