A CPR mask or pocket mask is a small device that is used to administer rescue breathing safely.
When delivering CPR during sudden cardiac arrest, there is a small chance that the rescuer can be exposed to potentially harmful elements such as bodily fluids including saliva, vomit, and blood. Using a CPR mask is an effective way to protect one's self from these substances.
When giving CPR, the rescuer will apply the mask to the patient's face creating a seal around the nose and mouth. The rescuer will then breathe into the one-way valve which allows air to flow into the patients lungs while preventing air or other substances from contacting the rescuer.