FSC-BT645 is an ultra-small size BLE 4.2 module, the module size is 10.8mm x 13.5mm x 2.0mm, it has a UART interface for transferring data and configuring the parameters of FSC-BT645 (via AT commands).
FSC-BT645 supports GATT(Central/Peripheral) and HID profiles, the UART baud rate is up to 921600bps, FSC-BT645 integrates a PCB antenna(Default version) and supports install an external antenna through a pin pad as well.