Product information:
Fabric:Spandex/Lycra 

Color: black, silver

Size information:
Size: S, M, L

Product features:
Using this mask can simulate the state of high-altitude training in the plain area. In the high-altitude environment, the air is thin, the oxygen content is low, and the blood cannot absorb oxygen normally as usual, so the heartbeat will be accelerated. Training under this ring can strengthen vital capacity, diaphragm, cardiac load intensity, anaerobic threshold, etc. So when you return to the low altitude environment, your sports performance or training will improve, so some people will go to high altitude for training.

Packing list:
Mask X1Set