This OLFA Endurance rotary blade set is built for 60 mm cutters used on medium to heavy cutting tasks in sewing rooms and studios. The pack includes two 60 mm (2.36 in) blades engineered to last longer between changes than standard OLFA rotary blades on fabric, batting, and other textiles. Install with the cutter locked, keep blades covered between uses, and replace as soon as cuts begin to drag or skip.