Flow meter: It allows you to precisely adjust the amount of oxygen the patient receives per minute, according to the instructions of the attending physician.
Manometer: It accurately shows how full the oxygen cylinder is at any given time, so you know when it is running low and when it needs to be replaced or refilled.
Pressure Regulator: It reduces the extremely high pressure of the oxygen inside the cylinder, converting it into a stable, low, and completely safe pressure for human breathing.