I am not an expert on this old spindle but it appears to be a table mounted auxiliary spindle with a Jacobs Collet chuck. There is an anti-rotate lock on the back end to allow the collet to be tightened/loosened with a pin spanner wrench. The spindle bearings feel nice. They rotate freely with no noticeable axial or radial movement. Collet chuck also works nice with no issues. There is only one collet however. This unit is heavy. Please email any questions. Thanks.