The basics Circular rotary replacement blade for 18mm rotary cutters used for quilting, sewing, and general crafts. The benefits This blade is made of high quality tungsten steel for unparalleled sharpness and superior edge retention. The uses Perfect for intricate and detailed cutting, this blade is ideal for small-scale projects, and for cutting curved pieces and tight corners. The bottom line For use with the 18mm Rotary Cutter (RTY-4) and Rotary Circle Cutter (CMP-3). Contains 2 Blades.