Olfa Stainless steel snap-off blades used in moist environments for wallpapering, window films, where rust is a concern. This blade made from high quality steel is produced using OLFA precise multi-step production process for unparalleled sharpness and superior edge retention. Long lasting, durable snap-off blade - a new sharp edge with each snap. This 9mm blade fits OLFA standard-duty knives. 13 cutting edges per blade.