Push yourself to the max in your workouts with a Sports Breathing Resistance Face Cover This mask will control you breathing and add resistance to make your workouts extra tough Using it overtime can help strengthen your lung capacity Simulates breathing conditions in altitudes from 5000 to 20,000 feet Adjust the resistance level easily with the tab on the front of the mask Mask is sealed around the nose and mouth for maximum effect Straps go around the face and on top of the head to keep it secure when exercising Straps are made from a breathable and sweat wicking material  Made from polyester and spandex, and medical grade silicone For only 20.99 pounds, rise to the challenge with this Sports Breathing Resistance Face Cover