The non-reversible mask covers the patient's nose and mouth and is fixed with an elastic cord around the patient's head. The mask has a connected oxygen tank ("bag"), with a normal volume of 1 liter, which is connected by an extension cord to an oxygen source. Before fixation on the patient, the reservoir should be filled with more than 2/3 of oxygen at a rate of about 15 liters per minute (l / min). About ₃⁄₃ air from the reservoir is used during the patient's breathing, then replaced by a stream of gas from an oxygen source. If the bag is completely inflated, the patient no longer has a source of air to breathe.
The mask is made of non-toxic transparent vinyl, tube length 2.1 m. Non-sterile.