[Introduction]：1.The original imported nRF52840 chip, supporting BLE 4.2 and B1. Original imported nRF52840 radio frequency chip. 2. Bluetooth 4.2 and 5.0 protocols. 3. It comes with high-performance ARM CORTEX-M4F core. 4. With 32.768K real-time clock. 5. Four-layer high-performance PCB board with excellent RF characteristics will help pass various certifications. 6. The module leads to most IO ports. 7. The module is not programmed, users need to carry out secondary development.