NFC tag. For this project an NTAG216 was used, as it is compatible with all smartphones and tablets equipped with NFC and has bigger memory available (888Bytes) than other NTAG tags. There are also bracelets, necklaces, cards,etc. with NFC tags embedded which can be bought directly and used for this project. However, the objetive will be to make wearables with Medical Passport official logo, as they will be easier to recognize by health professionals.