Elevation Training Mask 2.0 mimics the effects of High Altitude Training. When elite athletes want to improve their performance they go to high altitude levels to train. When they come back to sea level they perform much stronger, faster, and have increased endurance. For ultra runners who want to challenge themselves on mountain ultra's such as the UTMB (Ultra Trail Mont Blanc) and TDG this is the perfect compromise that can be used in conjunction with your normal training programme. Training Mask 2.0 is held on the face with a comfortable neoprene strap that over lays the air tight silicone piece that rests against the face. The multi-level resistance system reduces air flow through the patent pending flux valve system. Training Mask 2.0 promotes increased lung capacity by forcing you to inhale fuller deeper breaths. While using Training Mask 2.0 the conditioning of your lungs significantly increases along with endurance and diaphragm strength. Altitude resistance and Training Mask 2.0 There are various "Resistance Breathing" elevations with Training Mask 2.0 Training Mask 2.0 comes with an all in one package set. You do not need to buy anything else other than whats in the box. Machine Washable.