Mac buys from Mayhew as blank and badges them Mac or at least they used to. I've had a set of Mayhews since 99 and they are still in great condition. A little expensive but worth the money. When I worked in a tranny shop the big one was the only pry bar made stout enough to pry down the lower control arm on Dodge caravans. Everything else would flex.
Mayhew makes some great tools as far as my experience with them. I have one of there 60" prybars (7/8" bar stock) that I use for tracks on Bobcat track loaders. Also have a 42" bent tip and some brass drifts from them.