They would be knock-offs of the actual branded harness perhaps. I got my harness from eBay, it came in the original (sealed) Aviator Harness packaging and with the DVD, but there's no writing on the actual harness whatsoever. I'm skeptical as to if it's a legit harness, but the few times I've taken Coco outside in it, it's worked well and I can't find any faults with it.
I have three Aviator harnesses. All bought from a legit bird store, sealed in the package with the manufacturer contents. They don't have the brand written on the harness though. I've only seen a few that do from online bird friends. I think they used to have them 'branded' but the newer stock doesn't.