[flybouy]

Mine are made by Sendel (sendelwheel.com). It's been a few years but I think I was just doing a search on trailer wheels and stumbled across them.

I set them an email and they confirmed that the wheels are lug centric and to balance them would require a lug centric adapter.

Hispec also makes a lot of the same style trailer wheels. Recstuff.com sells the Hispec wheels.