The R1 Concepts drilled black brake rotor for 2000–2010 Westward Industries GO-4 (rear left) is listed as a drilled, black-finish replacement specific to the rear-left position for those years. It is supplied to replace the rear-left rotor and matches the described drilled surface and finish for the stated GO-4 application range.
R1 00-10 Westward Industries GO-4 Rear Left Drilled Black Brake Rotor