I think that this was the chuck that came with my Jet Mini. I use it with a 1 1/4 x 1" thread adapter on my Powermatic 3520B, and use a similar adapter for my Talon chuck which I keep with 1" threads to use on the mini lathe. I am too lazy to change out the chuck thread between use, and I get acceptable use. The 1 1/4 x 1" thread adapter also allows using faceplates and other items originally used on the mini on the larger lathe.