LOOPBACK TESTER PLUG SERIAL DB25 DB9
A dual ended serial wrap plug used to test serial ports for operation. This particular wrap plug has both db-25 and db-9. A very nice addition to any tech's tool kit.
Wiring Wired Together DB-25 port: 2-3, 4-5, 6-8-20-22. DB-9 port: 3-2, 7-8, 6-1-4-9.