Passenger backrest pads are available in three sizes: mini (8" w x 5" t), standard (12" w x 9" t) and wide (14" w x 9" t). All pads mount with three chrome screws and a triangular mounting plate. Note: Will not fit Air Wing upright. for best fit with Mustang seats, standard-height or higher uprights are recommended. Low and Mini uprights are not recommended.