I'm mostly rating this as a pricey ruler. The combo square attachments are of very iffy quality, with loose pins and cheap construction. They do work, which I suppose counts for a point to raise it from a 3 to a 4. They aren't of lasting quality, so I've detached them and use them occasionally. What I'm most pleased with is the rule, which I know I shouldn't get excited about, but I really like it. It has easy to read metric and inch scales, and is tough and smooth for drawing lines or cutting against. It lacks a hole for hanging it up, which I remedied. It's now my favorite shop ruler, and its combo square function is a distant secondary benefit.