Genuine Kingman factory replacement expansion chamber for the Spyder AMG and AMG Classic but can fit, Spyder 2000, Aggressor, and Aggressor XT. Solid Aluminum Construction. NO mounting screws included. Weight: 5.6 oz, length: 4 1/2 , height: 1 ½" , Width: 1 ½". May fit other models but NO guarantees! Hard to find!