NEUTRIK JACK PLUG RINGS - C series
Colour coding rings are available to fit over the shell at the base of the gland. They can be fitted whilst new connectors are being assembled, but can also be retrofitted to existing connectors.
This is done by unscrewing the gland, sliding the shell off the connector insert, fitting the ring over the back of the shell, then reassembling. The wire connection to the insert and contacts remains intact during the process.