The specific term "Pocket Mask" is the trademarked name for the product manufactured by Laerdal Medical AS.

A pocket mask is a small portable device used in the pre-hospital setting to provide adequate ventilation to a patient who is either in respiratory failure or cardiac arrest.

The pocket mask is designed to be placed over the face of the patient, thus creating a seal enclosing both the mouth and nose.

The emergency responder exhales through a one-way filter valve, providing adequate ventilation to the patient.

Modern pocket masks have either a built in one-way valve or an attachable, disposable filter to protect the emergency responder from the patient's potentially infectious bodily substances, such as vomit or blood.