I lost my Irwin combo box and ordered this as a replacement. I later found another field, but I refer to it as my combo box. It works better, is lighter and the accuracy is acceptable for my work. I think the rule slides better and is easier to assemble and assemble than other squares I've used. I even like the big pencils that come with it. I use them to create broad lines on parts that I run through multiple grinding cycles. I sand down the lines before moving on to the next finer grit. They do an excellent job of that. The device also has a metal stylus that is used when I need an accurate mark for cutting or chiseling. Overall very happy with this everyday use of the place.