Arbors ending with QC have a quick-change mechanism where no tools are needed to change the holesaw.3834-ARBR-9100, -11152 and -16152, are equipped with Power Driver™ that increases the strength and eliminates play of the holesaw by redistributing the load from the thread to the solid cap.Arbors can be used with carbide holesaws but we recommend to use the carbide tipped pilot drill, 3834-DRL-CT, for cutting abrasive materials.Arbors can be used for multi-construction holesaws but it requires changing the drill to 3834-DRL-L.HSS Pilot drill is included in all arbors, to be used for metal and wood applications.Easy change of holesaw with quick change mechanism