Rubber-sealed differential housings produced from high-quality Swiss 7075 T6 aluminum increases performance in warm conditions. Larger oil amount prevents the diff from overheating, extending its lifespan. CNC-machined from premium lightweight T6 aluminum. Black coated. Fits: XB819, XB818, XB817, XB8E19, XB8E18, XB8E17, XT819, XT817, XT8E19, GTX819