I bought these because I thought they would look cool on my truck. The size is based on the size of the bolt, not the actual size of the nut you may need. They looked good in the packaging but after putting a pair on my truck wheels they looked too small even though the lug size is correct. I've compared them to the old plain nuts I have and they're a lot thinner - they look more like a tube than a fastener. They might fit in a very light car but I figured they would break on my truck. Unfortunately, there's no meatier version of them - they might be cool in a truck if they were bigger and fatter. I sent them back and got my money back.