OLFA's largest rotary blade is designed for more heavy-duty projects. The blade, made of tungsten tool steel, cuts up to eight layers of fabric at a time. This blade is super sharp right out of the package and stays that way longer, thanks to its high-quality construction. The blades come in a convenient plastic storage container that also can be used as a safe disposal case. Use this blade to cut fabric, paper, vinyl, tarp, upholstery, fleece, felt and more. The blades fit any OLFA 45mm rotary cutter.