The line of null modem serial cables allows two DTE or DCE devices to communicate with no conflict in data transmission. The transmit and receive signals are crossed to ensure proper data transmission. Each null modem cable is designed with a rugged, overmolded construction that provides added strain relief and a solid connection each time.Plus 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.