SRAM Red 10 Speed Medium Cage WiFli Rear Derailleur Carbon Mid Black Silver 10spSRAM Red Rear Derailleurs New silent shifting with optimized AeroGlide Pulleys, ceramic bearings New spring fixed barrel adjuster New chain pulley cage adds precise chain management Titanium pinch bolt keeps a low profile while minimizing weight Compatible with other SRAM 10 speed drive train components Item Specifications Color Gray Black Weight 151g Intended Use Road Cassette Spacing SRAM 10 Shifter Derailleur Compatibility SRAM 10 Largest Cog