The Pinecar Rear Wheel Drive Chassis Weight is a metal weight designed to add approximately 2.5 oz to a pine wood derby car with weight concentrated toward the rear for rear-wheel-drive performance. The weight is shaped as a detailed chassis frame that mounts to the underside of the car, giving the finished build a realistic under-car appearance. It allows incremental weight adjustment and is compatible with standard pine wood derby block construction. Features: Approximately 2.5 oz metal chassis weight Rear wheel drive weight distribution Mounts to underside of pine wood derby car Realistic chassis frame detail 7/7/26 cs