This is a pocket mouth to mouth Cpr products, you can hang on your keyring, it is very compact and convenient. When someone needs CPR, you can find it right away. It is a one-way channel. It comes with flexible earloop Cpr Face Shield, operate more convenient. It is widely used in CPR training and AED training courses. for students, it is what a good gift. Material： Nylon Pouch, PE Face Shield. Size: Pouch 2"x 2" ; Face Shield 8 1/4 "x 7 3/4".