rear derailleur nx eagle 12 speed blackThis new NX Eagle derailleur features the proven SRAM 1x specific X HORIZON design. The larger, 14 tooth X SYNC lower pulley easily facilitates 11 to 50 and 10 to 50 tooth cassette capacity, and also adds to NX Eagle's overall smooth pedaling feel. The Type 3 ROLLER BEARING CLUTCH provides quiet, consistent performance and durability. Speed (RD): 12s Cable pull Ratio: X actuation Cage (RD): Long Max tooth: 50 Color (RD): Black Pulley bearings