Wow, who knew that there were so many different replacement knives for Lawson Pacemaker cutters and trimmers? We carry options for the Pacemaker I, II, III and IV in various lengths.. Choose from standard steel, high speed steel and tungsten carbide inlaid options. Just be careful to match the specs and hole pattern exactly with your current knife. Some Pacemaker models can use multiple different blades depending on the year of manufacturer.