It is not supposed to have ruler markings on it. You use your regular ruler, then abut the Slidelock against it, and remove the marked ruler to cut along the Slidelock, which is a quarter inch thick. Yes, it is expensive, but much cheaper than the cost of a significant injury with a rotary cutter, imho. Well worth the money. I think of it as cheap insurance. It works for me. I know without even trying that I would never be good at using the Klutz glove, on and off, back on and off, where is it now...underneath some fabric?