Arbors with ejector function for taking out the core easily.Arbors ending with EL are for Multi-Construction holesaws with All-round carbide drill included (Wood & Bricks).Arbors ending with ESM are for Bi-Metal holesaws with HSS drill included (Metal & Wood).Arbors ending with ES are for Carbide tipped holesaws with All-round carbide drill included (Fibreglass & Masonry).For enlarging existing holes you can also buy 3834-Upsize that is exceptional to use in combination with our ejector arbors.All arbors are packed in retail package.No need to spend time on core removal once the cut is performed.With the Quick-Eject arbor you can easily remove the core and save time and energy.The strong High-Alloyed steel body prevents wobble