- Parallel port Loopback (CheckIt) Used to verify that a port is working. This one works with CheckIt
- Parallel port Loopback (Norton) Used to verify that a port is working. This one works with Norton Utilities: Norton Diagnostics from Symantec
- Parallel port Loopback for Norton/PassMark Used to verify that a port is working. This one works with Norton Utilities: Norton Diagnostics and PassMark Software.
- Serial (Female D9F) Loopback for PC-check this adapter is used for giagnostic serial ports with pc-check software
- Serial port Loopback (25 CheckIt) Used to verify that a port is working. This one works with CheckIt.
- Serial port Loopback (25 Norton) Used to verify that a port is working. This one works with Norton Utilities: Norton Diagnostics from Symantec.
- Serial port Loopback (9 CheckIt) Used to verify that a port is working. This one works with CheckIt.
- Serial port Loopback (9 Norton) Used to verify that a port is working. This one works with Norton Utilities: Norton Diagnostics from Symantec.
- Serial port Loopback for PassMark (9 pin) Used to verify that a port is working. This one works with PassMark Software.
- Serial port Loopback for Passmark (25 pin ) Used to verify that a port is working. This one works with Passmark
