This is an essential internal adapter cable, designed to expand your PC connectivity, adding an external standard RS232 (COM) serial port. The cable connects to a 10 pin header connector on the motherboard (a standard connector for serial port), and ends with a male or female DB9 serial port to be mounted on the rear expansion slot of the case. With a length of about 20 cm, it facilitates installation and connection of the motherboard serial bus to legacy peripherals such as network equipment, modems, tax printers or diagnostic devices. Main technical specifications Function: Adapter for expanding an external serial port (RS232/COM). Motherboard Connector: 10 pin female IDC Header (typically 2 5 pin rows). External Side Connector: DB9 Serial Door (usually male). Length of the Cable: About 20 cm. Communication Standard: RS232 (COM). Application: Connection to legacy peripherals (modem, POS, industrial equipment, etc.). Mounting: Provided for mounting on a bracket expansion slot (bracket) of the case. Compatibility: Requires that the motherboard is equipped with a 10 pin COM header. Operating voltage: Standard RS232