Eliminates ANY chance of chain drop and quiets chain-slap! Tracked and grooved upper guide / backplate interface increases stiffness and eases installation Co-molded "HD" upper guide with softer durometer interior for silent guidance Integrated skid protects chainrings and glides over rocks and obstacles Whippersnapper™ lower guide Oval compatible Mounting hardware included and install possible with just a single 4mm HEX wrench. Swingset™ hardware Compatible with chainlines 49mm and wider ISCG-05 only From just 106 g (30-34t)