The main function of this product is to replace the traditional serial communication cable and convert the wired serial connection into a wireless Bluetooth connection, so as to realize wireless serial communication. It can be connected to devices with standard RS232 serial ports through the DB9 interface, and can communicate wirelessly with Bluetooth master devices such as mobile phones, tablets, desktop computers or notebook computers, and BT580 hosts that support Bluetooth BLE functions. Using the currently widely used Bluetooth BLE technology, the Bluetooth master device realizes serial communication with the serial device connected to the BT580 by monitoring and writing the Bluetooth characteristic values inside the BT580. Colour:Grey Material:plastic Package Contents: 1 x Rs232 Bluetooth Adapter 1 x USB Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.