The slip drive roll adapter is designed to work in the Harbor Freight Pipe Threader. The adapter is an external two inch octagon with a 7/8" square hole on one side and a 1" square hole on the other. If your slip roller requires a different size, please contact me for a quote. The adapters are currently $125 each and include free shipping.
You can see how I use the adapter in the YouTube video.
Check out this great video