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.