Serial Port Expansion The 3.3ft (1m) Null Modem USB Serial Adapter adds an RS-232 serial DB/DE-9 (female) connector to a desktop or laptop via a USB Type-A port. Secure the adapter to a serial device, using pre-installed and removable slotted D-Sub thumbscrews or install the included DB-9 Nuts for compatibility with other serial peripheral devices or cables.
