Blade for Challenge 305F paper cutters, standard inlaid high speed steel (AKI-IV) by Alliance Knife Company. This blade measures 35" long x 4.000" high and .438" thick, with 12 holes. (Challenge I.D. is 2238.) When ordering knives, please double-check the brand, model and serial number of your cutter, and measure your knife carefully. There is a 15% restocking fee for returned knives due to customer error.