These flh billet fender spacers are designed to work with arlen ness "hot legs" billet lower legs, american suspension " bagger legs" billet lower legs, or stock harley davidson 41mm flh & flt lower legs, not fx or xl legs.The 1-1/4" thick fender spacers can be used with a 6-3/8" wide custom front fender.The 1.0" thick fender spacers can be used with a 6" wide custom front fender.The 0.8125" thick fender spacers can be used with a 5-1/2" wide custom front fender.