The Shimano Tourney TY300 rear derailleur is fully compatible with all Shimano and SRAM 6- and 7-speed drivetrains. Utilizing SIS index technology and a longer cage for a max sprocket size of 34T, the Tourney rear derailleur is optimized for mountain, road, or touring applications where reliability and versatility are key. Long cage design accommodates up to 34T cassette SIS indexing for smooth reliable performance 6/7-speed compatible