I think it is comparable to their Turncrafter. It is a #1 Morse taper spindle with 3/4" thread. The variable speed is good, I love it in my Jet Mini. Light enough to take with you, too.
In fact I have the Grizzly----I've used it for two years now, and have enjoyed it---I did just replace the on/off switch. The downside of the Grizzly is no through headstock or tailstock---not too bad a deal on the tailstock, but makes it hard to get the pen mandrel out of the headstock. I'd go with a through head and tailstock for my next lathe---but, the variable speed is great.
