Shadow+ chain stabilizer provides a simple, lightweight chain control solution Mode Converter allows the derailleur to track different type of cogsets DH mode is a close ratio mode to track up to a 23T-28T low gear AM mode is optimized for a wider ratio cogset with a 32T - 34T low gear Saint-specific Shadow Plus design with integrated urethane bump stopper doubling-down on Shadow Plus functionality Shimano Saint RD-M820-SS1 10-Speed Rear Derailleur Short Cage