I've done a lot of work over the years where I had to measure up to a wall, cabinet or other structure. It always meant guessing as to how much to add to the measurement to get a tight fit. I saw this in a Youtube video about handy new tools and was amazed at the concept and simplicity. I immediately ordered on from Amazon and received it in about 2 days. I was in the process of adding a base shoe to finish out some work I was doing with my kitchen cabinets. When I used it according to the included instructions, I got the exact measurement I needed and the trim piece I cut fitted exactly. Great Tool!