Quadra-X ring design increases wear life and reduces friction by as much as 40% for maximum engine performance. MVXZ features Zero Stretch Technology that eliminates measurable chain stretch during the first 600 miles of use. Features lightening holes in side plates and large-diameter pins. 520 MVX/MVXZ chains include semi-press fit clip connecting link. 525/530 MVX/MVXZ chains include rivet connecting link.