[Waterproof Material & Size]: The NFC tag is made of environmentally friendly PET. Waterproof, smooth , wear - and shiny. Size: 21x11mm, Thickness: 0.15mm, ultra -thin. [NTAG213 Chip]: Transparent NFC tags embedded in NTAG213 chip, working Frequency: 13.56 MHz, 144 bytes memory. High scanning intensity, working distance is 0-10cm, depending upon the reader configuration. Valid period: 10 years, 100,000 times. [Features]: Ntag213 chip have read write locking functions, which can be repeatedly or only read. Set to be or reset after reading only labels. You can use them to quickly share your social information, music, connecting wifi, establishing smart homes, business information sharing and more. [Compatibility]: Writable and programmable NFC 213 Tags compatible with all NFC-Enabled smartphones and devices. (some models can only read data passively, and cannot actively write data). [Applications]: With self-adhesive backing, makes these NFC stickers can be used on different applications. (Note: Tags cannot be used on the metal and strong magnetic field). Colour:As Shown Material:PET Package Contents: 400 x NFC Tags Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.