I was using Cardas gold reference but I have moved and they are too short. I used several jumpers and some bare silver wire was the best. 10 ga I think but I did not see that on the net when I checked for it. I have some alleged Siltech but I got them on ebay and they may be fake, don't sound bad whatever they are. I was a VDH dealer and have some old very thick ones only in a short length. The First is a very good IC