Features: * Use to make linear and plunge cuts in to corners and flush against adjoining surfaces * Cuts thin wood, plastic, fiberglass, non-ferrous metals, thin sheet metal, hardened fillers, and window glazing * Semicircle is flat on one side * Universal fit system adapts to other brands * For use on Rockwell Sonicrafter and ShopSeries Sonictool models RK5139K, RK5140K, SS5120 What"s In The Box: * Rockwell RW8928.3 Sonicrafter 3-1/8-Inch HSS Semicircle Saw Blade - 3-Pack