Please note, both sizes will fit these frames however to accommodate a 28t or bigger cassette cog you will need the longer hanger The Specialized REV3 Alloy Road Derailleur Hanger Is a genuine Specialized replacement part. Available in standard or long lengths. Specialized Rev3 Alloy Road Derailleur Hanger Features  This hanger will fit the following bikes; Amira - 2010-2011, Roubaix Comp/Elite - 2009-2011, Roubaix Pro/Expert - 2007-2010, Ruby Comp/Elite - 2012, Ruby Comp/Elite - 2010-2011, Ruby Pro/Expert - 2012, Ruby Pro/Expert - 2008-2011, Ruby Sport/Base - 2013, S-Works Amira SL2 - 2010-2011, S-Works Roubaix SL - 2007-2008, S-Works Roubaix SL2 - 2009-2010, S-Works Ruby - 2008-2010, S-Works Tarmac SL - 2006-2008, S-Works Tarmac SL2 - 2008-2009, Sirrus LTD - 2012-2013, Sirrus LTD/Pro - 2007-2011, Tarmac Comp/Elite/Base - 2009-2011, Tarmac Comp/Elite/Base/Race/Sport - 2012-2013, Tarmac Pro - 2007, Tarmac Pro/Expert - 2008-201, Vita Carbon - 2014, Vita LTD - 2012-2013.