Allows full range of hole saws (14mm to 152mm) to be used SDS bits for use with SDS chuck power tools Hexagon and plain shank arbors for use with three-jaw chuck power tools Rework adaptor, enables enlargement of an existing hole Set contains: One SDS A1-1 6.5mm arbor; one SDS A2-2 9.5mm arbor; one A4 plain shank arbor; one A10 hexagon shank arbor, one rework adaptor and one ejector spring