Crosses the data transmission lines in straight-through serial cablesConvert your existing serial cables into null modem cables with the help of Cables To Go's Null Modem Adapters. A quick and easy fix for your DTE or DCE incompatibilities, connecting two RS-232 serial ports has never been so easy. Each cable will effectively cross the data transmission lines. With their molded design providing a solid connection, each adapter is shielded against outside EMI/RFI interference while giving you the flexibility to meet your connectivity needs.