While our tools are robust and built to last a lifetime they do have their limitations. Not every type of tree or shrub is going to be a good target plant for these tools.
It is important to know what you are working on so you can understand the composition of the roots and how they grow. For example, Oak trees are not a good target plant for our tools. While you still can pull smaller Oak saplings with our tools, their deep and strong tap roots make them difficult to remove once they are very large.