Ive installed the X, Y and Z axis version of this on a Precision Matthews mill. The instructions are garbage, but overall the units are ok. Ive needed more parts for each one. Hardware for Y and X, a spacer for the Z and i also had to bore the sleeve in the Z kit .003". The bore, as delivered, was .623". Bridgeports and all the clones Im aware of have .625" shafts for the knee handles, so i dont know what that is all about. The O.D. of the sleeve was concentric to the middle, so it was an easy fix. Just dial in on the O.D. and punch the bore out a little more on the lathe. As for the rest of the things that werent right, its hard to blame the manufacturer, as all these mills have slight differences. And besides, compare this price to a Servo or even an Asong.