I had the benefit of seeing this tool in action years before I needed it. In short, the house I renovated used small locks. To standardize the door hardware, I had to enlarge the lock holes on a dozen doors. A template and router would do the job, but at the cost of too much time and chaos. This brilliant yet simple tool has saved me countless hours of work. This is definitely a quality hardened steel tool. Whether you need to fix a single bug or a situation similar to mine, the tool will help you and you can count on it.