These racks are amazing. The packaging was beautifully designed and the manual was very high quality with color pictures and detailed instructions; I suspect the measurements are a little forgiving, but the instructions are so clear it's hard not to get them right. At first I thought I had bad rivets because the first one didn't pop and I had to fix it. When the second one didn't pop either, I tried a different rivet gun and it worked right away, so the rivets are high quality aluminum rivets. I love how high it holds up the hood of my Tacoma.