Protection: A CPR mask provides a barrier between the rescuer and the victim, reducing the risk of cross-contamination and the spread of infectious diseases. More effective breathing: The mask is designed to fit over the victim's mouth and nose and provide a seal, which can make rescue breaths more effective. One-way valve: Most CPR masks come with a one-way valve that prevents air or fluid from flowing back into the rescuer's mouth during rescue breathing. Lightweight and portable: A CPR mask is small, lightweight, and can easily fit into a pocket or first aid kit, making it a convenient tool for emergencies. Training aid: CPR masks are commonly used in CPR training programs to help trainees learn the proper techniques for rescue breathing and to build their confidence in administering CPR.