The BT-507 is a Class 1 Bluetooth USB Adapter and using Realtek RTL8761CUV chip complies with
Bluetooth 5.4. It combines a BT Protocol Stack for LM, LL, and LE.

The BT-507 is compatible with Bluetooth core specification v5.4 and supports dual mode(BR/EDR +Low Energy). It is compatible with previous versions, including v2.1+EDR.

For BR/EDR, it allows one active link in either slave mode or master mode. For Low Energy, it supports multiple states and allows one active link in slave mode. A BR/EDR link and an LE link can be active at the same time.