<https://calcuttaelectronics.com/product/hc-06-bluetooth-serial-pass-through-module/#webpage>
<http://schema.org/description>
"HC-06 Bluetooth serial pass-through module.USB protocol: USB v1.1/2.0.Operating frequency: 2.4GHz ISM.Transmit power: ≤ 4dBm, second stage."
<https://calcuttaelectronics.com/product/hc-06-bluetooth-serial-pass-through-module/>