CPR Microshield provides a physical barrier between a victim and rescuer during mouth to mouth resuscitation. The anti-reflux airway prevents backflow of victim's breath or body fluids. Designed to protect the rescuer while aiding in the administration of proper CPR technique, it has become the standard. The positive one-way valve inside the airway enhancing bite block is designed for maximum protection of the first responder. It also assists in keeping an open airway while performing the head-tilt, chin-lift maneuver.