3-1/8" HSS (high speed steel) semicircle oscillating saw blade can be used for cutting wood, plastic, fiberglass, non-ferrous metals, thin sheet metal, hardened fillers, and window glazing. Semicircle is flat on one side. Makes linear and plunge cuts into corners and flush against adjoining surfaces. For use with Rockwell SoniCrafter oscillating tools. Universal fit system adapts to other brands. 3 per pack.