PM Seal kit 137x4B calipers

Roland has taken the best of brake caliper technology, high quality precision machining and trademark RSD styling to create the next step in braking power for your V-Twin. With GP racing architecture and weight distribution, the extra rigidity maximizes your effort at the brake lever, stopping you faster with more feel. RSD brake calipers, in particular coupled with RSD Radial master cylinders, are the ultimate V-Twin braking system providing unparalleled feel and power.
Calipers feature differential bore pistons in 1.125" (28.6mm) and 1.375" (34.9mm) diameter that apply a different force at both the leading edge and the trailing edge of the brake pads for superior braking. Calipers come including brake pads, bleeder screw, 3/8"-24 banjo bolt and sealing washers & shim kit.

Note: Sportster models require the use of 9/16" master cylinder for single disc applications and 11/16" master cylinder for dual disc applications