"Mini Lowboy sissy bar kit, 9 inches tall, is for FX 4 speed 1972-1985 (except FXWG and FXST). Side rails are 1/8"" thick and the square sissybars are 9/16"" thick. Includes mounting hardware. The sissy bar uprights bolt to the side rails with button head screws from the outside providing easy access when changing to a different height sissy bar."