Olfa blades will not fit Fiskers cutters. The Fiskers requires a round hole while the Olfa hole is a more triangular shape with 3 little cut outs. If you try using this blade in your Fiskers, it fits but will not stay in position and handles as if your cutter has a flat tire. You can't cut that way. Rotary cutter blades are not universal. You should always keep your original rotary cutter package for reference or check your company on the internet. Most of them will give you a picture of the blade you need, describe it and even provide the diagram on how to reassemble your cutter after changing blades. The new Orbital rotary blade sharpening tool includes extra plastic bits to handle blades such as Olfa so that company also knows that rotary blades are not all standard. Do change your blade though because dull blades wreck your mat and may even cut you.