Shimano Deore Rear Derailleur

The SHIMANO Deore RD-M4120 rear derailleur is shown here in a long-cage version, suitable for 10- and 11-speed drivetrains with double chainrings.

Most importantly, it uses Shadow RD technology, found on higher-end models! This gives the derailleur a more compact design, making it less exposed to external elements (branches, rocks, etc.) that could damage it. The result is smooth, quiet shifting performance.