I think you'll find that the arbors are interchangeable among the different manufacturers. I use a Millwaukee arbor with my Blue Mole hole saws and it fit's OK.
Mike
In my bin of hole saws / arbors there are several kinds. The common ones we use have 2 sizes, one for larger hole saws and one for smaller (<1" or so). Like Mike said, they interchange with each other, at least the quality ones do.
The small just screws in, the larger has the stop pins that make it a lot easier removing the hole saw later.
I have some funky ones, one mandrel has flat sides on a round hole with no screw threads on the bit. The other kind has the thin saw blades nested together on a drive arbor that is supposed too hold one blade at a time, never used this kind and it looks cheap. Vermont american is not necessarily a quality tool.
Chilly