Way to extend video camera pole?

I have a ADC 722W mounted on a ceiling and I need to extend the poll mount out about 5" longer. Is there a good way to extend it? Seems to be a simple PVC item with tight threads like sprinklers.

I’ve not looked into this previously, but I would assume that the part is a standard size used by multiple products/applications, so there may well be a coupler option to add a second arm to extend the length. I can check with ADC to see what may be possible and report back.