As another reviewer wrote, this level is not entirely correct. I ended up buying it for a small project when my normal Stanley magnet level was lost. I didn't want to go back to HD so I ended up buying it to mount my wall speaker. Obviously he confused the horizontal plane, which was clearly visible when aligning the eyes. I ended up using another 24 inch leveler to fix this problem. I bought this device solely for the flexibility and convenience, but failed. I might get another Stanley block, which I should have done from the start. Not recommended.