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