The Sram NX Eagle 12 Speed Rear 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-pedalling feel. The type-3 roller bearing clutch™ provides quiet, consistent performance and durability. Sram NX Eagle 12 Speed Rear Derailleur Features Eagle™ technology provides an expanded, optimum, gear range making you fast on the flats, giving you control on the climbs and unleashing your speed on the descents. Eagle™ is a complete drivetrain system that was developed to be an integrated high-performance ecosystem. The engineering and testing that went into the development provide for maximum performance, safety, and long-term durability to ensure a great consumer ride experience. We guarantee this performance when eagle™ drivetrains are used as a complete ecosystem. For additional information, please contact your SRAM sales contact. Completely new rear derailleur incorporating our proven x-horizon™ design and new type-3 roller bearing clutch™ technology. Eagle™ ecosystem-engineered mounting system and cage lock™ positioning add robustness. Eagle™ pulley technology provides greater efficiency, crisper shifting and quieter operation. Sram NX Eagle 12 Speed Rear Derailleur Specification speed (rd): 12s cable pull ratio: x-actuation cage (rd): long max tooth: 50 colour (rd): black pulley bearings material: steel cage material (rd): steel