2 and 4 piston calipers machined from heat-treated aircraft quality, billet aluminum 5/8 in bore master cylinder required for single disc.

3/4 in bore for dual disc applications 2 piston calipers utilize two 1-5/8 in pistons.

4 piston calipers use four 1-1/4 in pistons Kits include brake pads, hardware and brackets GMA Caliper Model - F Includes correct axle spacers, anti-rotation arm, mounting bracket and hardware Made in USA This product can be used with Model Part# Harley-Davidson Dyna 92-99 BA4PRCKHD-1 Harley-Davidson Softail 87-99 BA4PRCKHD-2 Harley-Davidson Softail 87-99 BA4PRCKHD-3 Harley-Davidson Dyna 92-99 BA4PRCKHD-4 Harley-Davidson All 36-Up BA4PRCKHD-5 Harley-Davidson All Aftermarket Rigid 3/4 in Axle 10 in Rotor BA4PRCKHD-5 Harley-Davidson All 36-Up BA4PRCKHD-6 Harley-Davidson All Aftermarket Rigid 3/4 in Axle 10 in Rotor BA4PRCKHD-6