Anesthesia Bag Mask These facemasks have a cuff that allows for a complete seal to be achieved between the mask and the patient's face. Product Details FEATURES These facemasks have a cuff that allows for a complete seal to be achieved between the mask and the patient's face. Anesthetic facemasks can therefore be used to deliver non-invasive ventilation (NIV). In order to ventilate with an anesthetic facemask you'll need a pressurized gas source (anesthesia gas supplies) such as a cylinder or gas wall supply. If no pressurized gas source is available, a self-inflating bag will allow for positive pressure-ventilation through an anesthetic facemask.