This is a replacement damper for the following Cannondale Lefty forks: 2013-2015 Lefty 26", 100mm 2011-2012 Lefty Speed 100mm 2009-2010 Lefty Speed SL and DLR2 110, 100mm 2009-2010 Lefty 29'er SL and DLR2 80, 70mm