Utility knife blades snap off blade ht mm=25 Extra heavy duty, snap off blade made from high quality carbon tool steel for sharpness and edge retention; 7 cutting edges per blade; cuts drywall, roofing, linoleum, carpet, sod, insulation board and more. Blades for knife H-1, XH-1 (SKU #'s 252.9519 a nd 692.1118).