Shimano Tiagra RD-4700-GS Rear Derailleur The Shimano Tiagra 4700 Rear Derailleur provides you with consistently smooth and reliable shifting. With trickled down technologies from the Dura-Ace line, it offers serious entry-level riding performance at a cost that can't be beat. You have the option to run a cassette with up to 34t, giving you the advantage in steep grades. Specs Model RD-4700-GSSpeeds10Low sprocket_Max. 34T (Front double), 32T (Front triple)Low sprocket_Min. 28T (Front double), 25T (Front triple)Top sprocket_Max. 12TTop sprocket_Min. 11TMax. front difference16T (Front double), 20T (Front triple) | Shimano | Tiagra 4700 Rear Derailleur 10 Speed, Medium Cage