Does anyone know the diameter of the ball bearing in the OEM slave? I know the Oberon unit uses an 8mm ball but some how the ball is missing from mine and you can only purchase the slave as a unit for $180.

Oberon slave is $120 last I checked. Did you try to call them and ask if they would sell you the ball only?

I've not tried calling them as I'd like to try and get a replacement before Saturday. I figure a balls is a ball is a ball so if I can get the size of the OEM ball then I can get one from a local shop.

It looks like the OEM slave uses a 7mm ball, anyone correct me if I'm wrong.