I bought this hoping it would serve my purpose without spending $80 for a "professional" square. All my life I've had different types of squares, but I guess it wasn't until I needed one of my designs to be "accurate" that I realized that nothing I had was good enough. I've always worked with wood, but I've never created anything where it was important to me to be "rectangular". Not to mention that I "assumed" that all squares are square. Well, it's a crocodile. It's not like this! I didn't expect this combo square to be perfect, but so far I'm very happy with its accuracy. I don't have a caliper to test it but from the checks I've done it's fine and square enough for my application so far. I would buy this again. I'd say for the money it's worth a try.