Shimano SLX M662 9 Speed Shadow Rear Derailleur: Tough, aggressive & light weight All-Mountain SLX rear derailleur using revolutionary features from XT & XTR at an affordable price point. Shadow features a super low profile design that reduces the risk of damage from trail side hazards. GS cage should be used with single & double chainsets only & the SGS cage should be used for use with triple chainsets. Single tension spring prevents contact with the chainstay resulting in a silent ride Direct cable routing prevents snagging from any trail side hazards Alloy & steel construction leads to lower weight without compromising strength & durability Two fluorine-coated link pin bushings aid slick shifting on the trails High rigidity wide outer link braces the pulley body to increase pivot joint rigidity resulting in a crisp shift Strong return spring for a positive shifting feel GS cage should be used with single & double chainsets only SGS cage for use with triple chainsets Mega 9, 8 & 7 speed compatible For use with 32 or 34 tooth rear sprockets, total capacity 35 teeth Top normal spring for use with Rapidfire shifters Average weight 254 grams (GS)