APEX XPLR REAR DERAILLEUR EAGLE 52DThe Eagle development range on a bike fitted with road handlebars? Champagne! The Apex Eagle rear derailleur ensures fast, quiet shifting on our Eagle 12-speed cassettes, and the chain management system specific to 1x configurations keeps the chain where it needs to be. It's our best innovation for road bikes and mountain bikes, all in one system.FEATURESCompatible with Eagle 50 or 52-tooth sprocketsWorks with Apex shifting levers and Eagle 12-speed controlsWorks with Eagle chain Roller Bearing Clutch controls chain tension for reliable shiftingThe X-HORIZON straight parallelogram design restricts movement to the horizontal axis only, This makes unexpected gear changes impossible, and reduces the force required for shiftingCage Lock technology enables time-saving wheel changing or chain installation