It is recommended not to insert or unplug a serial port while it is energized.When inserting or unplugging the serial port, at least one end should be cut off, otherwise the serial port may be easily damaged. This cable's fully molded connector with thumbscrews can provide you with a quick and convenient connection every time. Just loosen the screw to disconnect, then connect and tighten firmly to make the connection. With high compatibility, it can meet the needs of notebooks and desktops to connect to serial computers, digital machine tools, set-top boxes, industrial instruments, etc. Split a DB9 9 pin female connector into two DB9 9 pin male connectors. This is an ideal and cost-effective way to connect two DB9 RS-232 serial peripherals to a PC source. Package : You will get 2pcs DB9 serial splitter cable.