It specifically fits the Milwaukee 48228435 PACKOUT Compact Organiser. The insert was specifically design to fit a Lenox 26 piece set. I am unsure how it would suit other brands or set so I am unable to confirm if this will work outside of this specific set: https://www.lenoxtools.com/pages/308042000g-contractors-big-daddy-speed-slot-hole-saw-kit-26-piece.aspx The design will accommodate the standard arbor bits that come with the Lenox set in addition to the Lenox quick change arbor's: https://sydneytools.com.au/product/lenox-1779669-5l-hex-arbor-snapback-to-suit-14mm-30mm-hole-saws https://sydneytools.com.au/product/lenox-t1779670-6l-hex-arbor-snapback-to-suit-32mm-152mm-hole-saws https://sydneytools.com.au/product/lenox-t1779772-2l-hex-arbor-snapback-to-suit-32mm-152mm-hole-saws