5 Black Mini CPR Breathing Barrier Keychain Kits Face Shield Prevents Mouth-to-mouth Contact and Risk of Infection or Contamination Breathing Barrier with One-way Valve Protects You While You Save Someone's Life 2"x2" Great for glove compartment， boat， purse， keychain or home Use for CPR first aid to help someone who has stopped breathing or whose heart has stopped. Contents Included: 1 Keychain nylon pouch， 1 Breathing Barrier with one-way valve. Directions Remove breathing barrier from keychain kit and place on victim's face with instructions facing you and with the one-way valve directly over victim's mouth. Proceed with CPR First Aid.