by OLFA Dull blades will fatigue you quickly when cutting fabric. And buying replacement blades in a multi-pack is an economical way to go! Made from high-quality tungsten steel, these rotary blades cut multiple layers of fabric at a time. Each package contains 1 replacement blade that fits most 60mm cutters. "With each new project, a new blade is in order." ~ Sharyn CraigThat's really all we need to say!