Mainly aesthetics, I wanted a sleeker look to the roof line without chopping the cage. Saw them for sale from Dragon Parts, but couldn't justify $136 for them. So a couple pieces of 1/4" ABS and a cardboard template made my own. Compression fit, no drilling or hardware. I thought I would hit my head as well, but they have no effect on getting in and out. Took it for a ride to test them, come to find out they actually ARE useful. Stopped quite a bit of mud, cut the wind down more that expected, and best of all deflected the low hanging branches that used to slap me in the face lol. But mostly, I just thought they look cool.