The notched top bar is about 1/2" thick, beveled to 1/4" at the top. Behind and below that is a 3"x3" square tube. (It's from China, so dimensions are approximate.) The third piece is the SSQA adapter cross piece angle. Not shown is the back stop, it doesn't have one .I'll measure it later. The top is tapered, it can only be so thick and fit in the fork bracket. It also has some additional meat further down. Looks very similar to the picture of the Pro Works.