Raytac released the AT Command Evaluation DK Board.
Part No.: MDBT42Q-AT-UART
Raytac AT-Command nRF52810 Module:
More information about UART service (AT Command), Pls refer to below link
UART service, as known as NUS (Nordic UART Service) is the most common and easy way for BLE relating IoT Implement.
Customers who is familiar with Classic Bluetooth are used to call as SPP service.