Biting, breathe freely. Respirator side have adjust the volume knob, can according to their proper adjustment. Respirator external, it is a "breathing", is actually a small funnel shaped like things, rubber texture, you bite, funnel in your mouth open, it is hard to fall off, unless you draw it out. Divers back cylinder, filling in the compressed air, not oxygen - divers not critically ill patients, not pure oxygen. To deep said: senior divers will involve the use of high concentrations of oxygen: only at high altitude or long time or other extreme conditions when diving, use. Otherwise, it is compressed air, namely: ordinary air we breathe at ordinary times, just are filling in the form of high pressure into the bottle (with professional machine, about the size of two or three cubic metres). Breathing, is breathing normally. Inhalation: you use the gas in cylinder; Exhale, spit directly: outstanding gas from breathing on both sides of the head 

Biting, breathe freely. Respirator side have adjust the volume knob, can according to their proper adjustment. Respirator external, it is a "breathing", is actually a small funnel shaped like things, rubber texture, you bite, funnel in your mouth open, it is hard to fall off, unless you draw it out. 

Divers back cylinder, filling in the compressed air, not oxygen - divers not critically ill patients, not pure oxygen. To deep said: senior divers will involve the use of high concentrations of oxygen: only at high altitude or long time or other extreme conditions when diving, use. Otherwise, it is compressed air, namely: ordinary air we breathe at ordinary times, just are filling in the form of high pressure into the bottle (with professional machine, about the size of two or three cubic metres). Breathing, is breathing normally. Inhalation: you use the gas in cylinder; Exhale, spit directly: outstanding gas from breathing on both sides of the head