6. Why the NFC is not that sensitive sometimes?

A: NFC belongs to the near field communication technology. Both NFC sensing areas of the mobile phone and BTR3 must be close to each other to be sensed. The NFC power of each mobile phone is also different (especially the NFC sensing sensitivity of the metal case mobile phone is low). With the case on, some phones' NFC would become less sensitive. It is recommended to remove the phone case and try again.