TRP EVO Rear Derailleur - 12-Speed High Performance Your drivetrain shouldn't hold you back while you're out on the trail. If you're looking to upgrade your bike or you're building up something fresh, then you'll love TRP. The TRP EVO Rear Derailleur is a high-performing 12-speed rear derailleur that offers numerous features that offer smooth and efficient operation. It features an Integrated Hall Lock Lever that stabilizes the rear derailleur to eliminate drivetrain noise, Horizontal Parallelogram that stabilizes the rear derailleur over rough terrain, Instant Silent Clutch that prevents unwanted chain slap and noise, a Cage Release that releases cage spring tension and offers easy wheel removal for maintenance, and a carbon outer cage that provides strength and weight savings. Features Integrated Hall Lock Lever stabilizes the rear derailleur to eliminate drivetrain noise Horizontal Parallelogram stabilizes the rear derailleur over rough terrain Instant Silent Clutch prevents unwanted chain slap Cage Release that releases cage spring tension and offers easy wheel removal Carbon outer cage provides strength and reduces weight Smooth operating 12T upper and 14T lower pulley wheels that feature sealed bearings to provide protection from the elements | Trp | Evo Rear Derailleur - 12 Speed Black/silver