The R1 Concepts slotted brake rotor for 2006–2009 Buick Ascender applications is a black-finished replacement rotor specified for the front left position. The product description lists the slotted braking surface and the front-left fit, making it directly relevant for service or repair of the front-left brake on Ascender models from those years.
R1 06-09 Buick ASCENDER Front Left Slotted Black Brake Rotor