The R1 Concepts drilled-and-slotted brake rotor is a black rear-left replacement specified for 1985–1991 Subaru GL-10 models. This drilled-and-slotted rotor serves as a direct service option to renew the braking surface and help disperse heat and brake pad deposits under normal use. It is sold as the single rear-left rotor for the Subaru GL-10 vehicles listed in the source.
R1 85-91 Subaru GL-10 Rear Left Drilled & Slotted Black Brake Rotor