This 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-pedalling feel. The Type-3 Roller Bearing Clutch™ provides quiet, consistent performance and durability.   Features 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..   Specification Speed: 12. Cable pull ratio: X-Actuation. Cage: Long. Max tooth: 50. Pulley bearings material: Steel. Cage material: Steel.