Lightweight yet ultra-strong right back upright molded from unique EXTREME composite product. Features larger outside 8x16x5mm ball-bearing for increased reliability and life-span. Makes the trunk of vehicle exceedingly stable. Improves bump consuming and managing in hotter conditions. Fits XB8, XB8E, GTX8'19 and much more current, GTX8E'19 and much more current, XT8'19, XT8E'19