5-Pack Quilting Bee 45mm Rotary Cutter Refill / Replacement Blades (RB4505) HIGH-QUALITY. SKS-7 tungsten-steel blades will stay sharp longer than others. EXTRA SHARP. Cuts up to 6 layers of fabric or batting. GRADUATED MARKINGS. Can be used for rough measurements without a ruler. USE IN ANY 45MM CUTTER. Will work in all major brands of rotary cutters, including Olfa, Fiskars, Havel, Martelli, Gingher, and Clover. But use Quilting Bee's rotary cutter for best results. SATISFACTION GUARANTEED. Quilting Bee&reg; stands behind our products.