I had old original Irwin Heavy Duty clamps - they fit but needed sanding/shaping - original pads don't seem to be available (close look) - so didn't like it, had to replace the shoe reshape support on the widened part of the shoe to fit the clip but after I shaped them they worked just as well/or better than new ones - my clips are about 10 years old and I use them almost daily - the original pads are right now is starting to fail - so glad I found these replacement parts - but if the original pads were available this would be a 5 star rating