These are the standard seat belt swivels with mounting bracket. This swivel set will bolt up to an older plastic air chair seat tower without modification, and a newer aluminum air chair seat tower with slight modification. The mounting brackets bolt to your seat tower in place of the footman loops using the same 4 bolts that previously held the footman loops on and has 3 locations to mount the swivels on them. This swivel kit includes (2) belt loops, (2) swivel mounts w/ nylon bushing, (2) mounting bracket, 2 5/16" x .25" FHCS SS bolts, & (4) 1/4-20 x 1" BHCS bolts.