I have a 12 inch Incra ruler and the only difference between it and this one is that the Incra also has pencil cutouts on the trailing edge. Not sure how rust resistant this one is. It comes disassembled and is very easy to assemble. My complaints about this product are as follows: 1. Factory quality control may be flawed. Mine came with 2 deep dents on the other end. I can smooth it out, but I can affect accuracy on that scale. 2. He doesn't hold the square for too long. The tolerance for mismatch is quite large when installing a square fence. I've tightened it as far as I felt comfortable and due to the fair play of the mounting screws, the angular accuracy doesn't last all that long with constant use.