It is the first concrete hole saw I have purchased. The only thing I noticed is that it does not have a hex key for changing the diamond hole saw. Only a wedge-shaped pin. This is for information regarding this specific concrete hole saw.
After drilling some holes in brick, the small thread on the sds axis, which screws and holds the hole saw in the drill, broke. It now requires a different sds plus axis. Unless I go to a lathe and turn the second larger thread on the axis for larger hole saws and apply it to this specific one. But other brand hole saws (in a set) have the axis and the hole saw with the immediately larger thread diameter.