Begin Industries 10 Black NFC Tag Stickers 25mm (1 inch) Round - 888 Bytes NTAG216, Compatible with All NFC-Capable Phones (Black);

Features:
888 bytes or rewrite-able and optionally password protected or permanently lockable storage (600%+ the amount of storage as an NFC NTAG213)
Once Locked the tag cannot be unlocked
Black PET sticker is water resistant
NFC Forum Type 2
Frequency: 13.56MHz
Operation Temperature: -20°C~+80°C (-4°F~+176°F)
Storage Temperature: -20°C~+80°C (-4°F~+176°F)
Will NOT work on metal surface (there are special tags noted as "on-metal" for these applications)
Easily concealed by being plain black and the smallest size an NTAG216 can be
Comes in Resealable Bag for storage

Applications:
Use withShortcuts app on iPhone to trigger automations.
Store a web address that will take any NFC smartphone right to your website (or Twitter, Facebook, Instagram, Pintrest, etc.)
Store your Credit Card Issuing Bank's Contact Number and stick on the back of your Credit Card to easily call them up if you have any issues.
Automate repetitive tasks on an NFC enabled smartphone. (example: Turn Bluetooth off, turn Ringer off, unlock screen, etc.)