These are good clamps and the dimensions are given for the product. I used to buy these clamps from Harbor Freight and they are the same just much larger. I think the best way to explain this is that the sizes don't really prepare you for the size difference if you're used to large ones. They are an inch shorter but also much smaller in girth. Like I said, these are good clamps. Just be mindful of the size and make sure you don't need big ones.