Arbors for small holesaws Ø14-30mm:.3834-ARBR-730 with triangular shank.3834-ARBR-630, -930, -1130 with hexagonal shank.Arbors for big holesaws Ø32-210mm:.Arbors ending with QC are arbors with quick change mechanism where no tools needed to change 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.We recommend not to use arbors with 8.5 mm (11/32") shank for holesaws above size 100 mm (4").HSS Pilot drill 3834-DRL is included in all arbors, to be used for Metal & Wood applications.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.All -C arbors are packed in retail package and the others are packed in a cardboard boxes with an instruction leaflet enclosed.Arbor for holesaw sizes 14-30mm.Choose correct shank size for your machine