I'm a simple handyman and my only power tool for cutting wood and completing projects is a saw. I can now safely and easily mark distances and straight lines (including angle lines) with the speed square, and I can now easily cut straight lines using the speed square as a guide (see YouTube video on speed squares). This simple tool has made DIY projects infinitely easier and more accurate. I can't speak for accuracy like some pros can, but it gets the job done for the main projects I work on. Of course, the markers are just indented and not colored differently, but I have no problem reading them. And yes, it's some hardcore plastic, but if I wanted a metal square with speed, I'd spend the extra money.