I ordered 10 of these it was like $12. They are re-programmable and come unformatted. You need 4.0.3 ROM (although not all 4.0.3 ROMS work they need the correct updated binaries) to write and read these. If you're on 4.0.2 and sticking to it then you need to request they be pre-formatted to NDEF iirc. I'm on Romans build 14 and they write and read these with no issues. Fabs/bigxies, kejars Gummy, and Romans build 14 are three 4.0.3 ROMs confirmed with NFC working on these stickers I've tested them.