Outus 90 Pieces Swivel Clasps Lanyard Snap Hook Lobster Claw Clasp 40 Pieces and Keychain Rings 50 Pieces We are the Real Training Mask : We have pioneered and have become the leader in performance breathing devices. Genuine TrainingMask breathing exercise devices were engineered to apply variable levels of tension to the breathing muscles by controlling air flow which increases tension on your breathing muscles. Ergonomic Design : he workout mask is made of non-toxic silicone body and adjustable elastic non-slip straps,one size fits most people. It can reduce the risk allergic reactions and skin irritations.Soft and smooth material can fit your shape of face perfectly