4 piston 1-piece designed caliper Billet aluminum 5/8 in bore master cylinder required for single disc.

3/4 in bore for dual disc applications GMA Caliper Model - M Made in USA This product can be used with Model Part# Harley-Davidson Softail 87-99 BA4PSRCKHD-1 Harley-Davidson Softail 87-99 BA4PSRCKHD-2 Harley-Davidson FXST 00-05 BA4PSRCKHD-3 Harley-Davidson FLST 00-06 BA4PSRCKHD-3 Harley-Davidson FXST 00-05 BA4PSRCKHD-4 Harley-Davidson FLST 00-06 BA4PSRCKHD-4