One fit, 4″, segmented hss tin storm blade, arbor ensures proper fit on oscillating tool, titanium storm series, use high speed steel blade for fiberglass, carbon fiber, 20 gauge sheet metal & harder woods, titanium coating will make blade cut faster & last longer because it keeps blade cool, fits fein, bosch, makita, dewalt, rockwell, porter cable, milwaukee & more oscillating tools, adaptor included to fit dremel quick release & old rockwell.