Srams best rear derailleur in wireless electronic version.

The weight is kept down by using carbon arms and an aluminum body.

The rear derailleur only works with the Sram Red eTap shift lever.

The battery is located directly on the rear derailleur, so it does not require any wires.

The short arm can hold up to 32 teeth on the cassette.

The pulley wheels come with ceramic bearings.

The rear derailleur is made to run best with Sram PowerGlide and HyperdomeX cassettes.