THESE TAGS ARE COMPATIBLE WITH ALL NFC ENABLED DEVICES. STICKERS CAN BE RE-WRITTEN THOUSANDS OF TIMES.These stickers are blank white, 30mm diameter circles. These are PVC material NFC tags for extra durability. This quarter sized white NFC Sticker is backed by a NTAG 203 chip. It stores up to 144 bytes of user data which can be made read-only. Note: NFC TL is able to associate tasks with a Unique ID (UID). This allows for larger sized tasks to be initiated without having to worry about the capacity of the tag. It is metal-isolated, which means it can be placed directly on metal. It will work on metallic surfaces such as your macbook pro. This sticker is made from PVC.  It's tougher than paper being more water and weatherproofThey can be written over and over again or locked down for one-time writes. Be warned: these tags are not pre-formatted, so they will not work well on Ice Cream Sandwich versions 4.0.1 and 4.0.2.