The lights are mounted from the top with recessed allen head bolts! The holes in the bottem and back of the bar, are for two reasons! Shave weight, and so I could get the lights in, and wired. If a guy wanted bigger lights, you'd have to start with a bigger piece of tube! But if ya get much bigger, it might look like crap. I built this bar cause I wanted lights, but still needed to get into My garage. Thanks to everybody that likes it!