With the P450-000 Null Modem Adapter Kit, you can set up PC-PC Serial connections up to 100 feet (30.5 meters) apart using readily available Cat5/Cat6 Ethernet cables. The finished connection results in a Null wiring configuration: 1+6 - 4, 2-3, 3-2, 4 - 1+6, 5-5, 7-8, 8-7, with Full Handshake capability. Slotted, knurled thumbscrews provide easy and secure attachment to your computers.