Material: Non-toxic silicone
 Size: 45-65mm diameters, adjustable (Adult or Children)
 Chip: NFC 213
 Working frequency: 13.56Mhz
 Protocol: NFC Forum Type2
 Memory: 144 bytes for user read-write
 Package: 1pcs/pack
  

 NFC Forum Type2 ISO14443A  
 Read-write 144 bytes user memory  
 Reading Distance: 1-5cm  
 Compatible with most Android NFC phone  
 Non-toxic silicone environmental protection material