Medinc's Blood Bag Key charm (O-) Blood Bag (containing coloured water) with blood type printed on it String loop allowing you to attach to your mobile phone, key ring, key chain belt loop. Great for letting emergency services know what your blood type is in case of emergency. Great gift for phlebotomist. nurse or doctor 30 day satisfaction guarantee, if you are not 100% satisfied with your item for any reason, it can be returned for no cost within 30 days of receiving. Please contact us for further information.