Rear brake caliper kit (2 piston) for Sportster 1979-1981. These custom rear 2 piston calipers with hanger brackets and complete hardware kits are designed to replace old, worn-out calipers and brackets. GMA calipers are machined from billet aluminum, clear anodized and feature dual pistons for the best braking possible. The hanger brackets are blanchard ground to specifications and carefully machined.