Do you have a paver that needs a 4" hole? This is your tool. Do you have a concrete slab that needs a 4 inch hole? It will. Do you have a wood wall that needs a 4 inch hole? Take this tool. We used it to make a 4" hole in a 2" concrete block. We stuck this tool in a cordless drill, used a water hose to keep the rock wet, and this thing went through the foam like a hot wire. I was looking for something else that needed a 4 inch hole.