Training Mask Original Chrome Series 2.0 for Fitness Running Breathing Mask, Resistance Mask, Elevation Mask, Cardio Mask, Endurance Mask for Fitness

Great mask; first I would like to note the bang for buck. Where you receive the mask,sleeve, adjustable sleeve, different gauges for different settings, and stickers. It also looks amazing and you can tell the product is well put together and has a lot of effort put into it. Also works amazing, you can literally feel your body working for every breath as you work out pushing your self to your limits. The only con to this is, I do not recommend this for beginners. This mask can be hard to breath in at the lowest level for some people. But if you are a athlete or person who likes to a challenge and looking to improve this is the perfect product for you.

Love the elevation mask. Don't know about helping put on muscle, but it sure exercises the lungs promptly.