I don't know, the main thing this tool does is cut the roots and even then on a few that had roots 6" and bigger, I had to cut them with a chainsaw.
A bigger machine would have been able to cut even them, but not my 38hp. I could not do with my 66" bucket what I can do with this 3" foot and
3/4" blade. First , on some trees you can't get all the way around them with a bucket, with the reach of this tool I can get around most trees and
I am not digging massive holes all the way around, just a small trench. The last oak tree I took down, it was close to others and no way could
you get in with the bucket. I was able to drag the foot on all 4 sides which cuts 2 to 3 ft deep and when I pushed it with the foot it came out roots
and all. I guess the tree company that made it knew what they were doing.