Comes in a set of (2) two, 2 left hand side (front and rear) Foot Rails and 2 right hand side (front and rear) Foot Rails. Fits to the Rivian R1S's existing mounting holes. No drilling or modification required. Foot Rails follow the contours of the vehicle's roof line providing a sturdy base to fit the Front Runner Slimline II Roof Rack. Made of high strength steel and sealed with the same durable, weather resistant powder coating as the Front Runner Slimline II Roof Rack. Installation hardware and fitting instructions included.