The R1 Concepts Geo-Carbon drilled-and-slotted rotor is supplied as a single replacement for the rear-left wheel of 1998-2005 Buick Park Avenue models. The product description names a Geo-Carbon rotor with drilled and slotted surfaces offered by R1 Concepts for that rear-left position. This overview follows the explicit fitment in the source and presents the rotor as the rear-left replacement for the Park Avenue years listed.
R1 98-05 Buick Park Avenue Rear Left Drilled & Slotted Geo-Carbon Rotor