I have a 40 volt Ryobi drill head that has an excellent root cut and an 8 inch double flute bit. However, I need a 12 inch hole in my sandy Florida. Boden, so I ordered this thing. It's not totally useless, but it's almost there. When I first used it, it didn't do anything. It doesn't go into the ground at all. It was completely ridiculous. After careful investigation, I discovered that this thing has a left-handed flute! Luckily Ryobi's drill head has a reverse switch, so I put the machine in reverse and the drill started digging. However, this did not last long. The first tiny spike it encountered, the drill just passed over it without cutting, twisting it uselessly. I took the thing off, installed an 8" ryobi drill bit, and sure enough it cut through every root it came across, including the size of my finger. This almost useless 12" drill only has 1 flute running in the wrong direction, while the 8" Ryobi bit has 2 flutes running in the right direction. One edge of the ryobi groove has saw teeth that appear to be grasping the roots, easily cutting through them. The other groove has a sharp edge. precise hole placement. This 12-inch drill has a split, shovel-like tip that picks up debris as you cut. It's not a useless piece of junk, but it's almost there.