I wasn't paying enough attention when I bought "4 inch" lights. They are, in fact 4 inch, but that is the entire housing diameter. The lens part is maybe 3 inch within the bezel. When I first opened the box, I thought the small lights weren't going to BLAST like they do, but I installed them anyway, and was completely surprised! The smallish size doesn't look that bad on the truck either despite being about the size of grapefruits. As for the beam pattern, it's a not-too-narrow spot that blazes See full review