Renthal Ultralight Rear Sprockets start their lives off by getting CNC machined from 7075 T-6 aluminum, an alloy that is prized for its strength and wear resistance. A near perfect material for sprockets. The alloy is light weight, and with Renthal's drilled patterns, the Ultralight weighs up to 66 percent less than comparable steel sprockets while retaining a comparable lifespan. The material isn't the only thing that promotes longevity. Self-cleaning cuts are machined into each chain groove to clear away mud and debris from sensitive wearing surfaces, so both the sprocket and chain are kept clean of abrasive particles. There's almost no downside to putting a Renthal Rear Sprocket on your motorcycle or ATV. Also Fits: Honda CR250R 1992-2007 Honda CR500R 1988-2001 Honda CRF150F 2003-2009 Honda CRF150F 2012-2017 Honda CRF230F 2003-2009 Honda CRF230F 2012-2017 Honda CRF250R 2004-2018 Honda CRF250X 2004-2009 Honda CRF250X 2012-2013 Honda CRF250X 2015-2017 Honda CRF450R 2002-2019 Honda CRF450RX 2017-2019 Honda CRF450X 2005-2009 Honda CRF450X 2012-2017 Honda XR400R 1996-2004 Honda XR650R 2000-2007