6ft DB9 female to female null modem cable connect two PC serial ports and allows two DTE or DCE devices to communicate with no conflict in data transmission. Transmit and receive signals are crossed to ensure proper data transmission. Each null modem cable is designed with a rugged, over molded construction that provides added strain relief and a solid connection each time. The cable is foil shielded for EMI/RFI protection from surrounding office equipment and fluorescent lights. Thumbscrew connectors provide a fast, easy connection every time.