Manufactured by Factory Spec Rear Sprocket for Honda ATV 39 tooth, rear steel Sprocket 520 pitch Made in China Sprocket may not be the stock size for all of the models it fits. When changing sprocket sizes, you might also need to change your chain length Fits the following 2004 Honda TRX450R Sportrax 2005 Honda TRX450R Sportrax 2006 Honda TRX450ER Sportrax 2006 Honda TRX450R Sportrax 2007 Honda TRX450ER Sportrax 2007 Honda TRX450R Sportrax 2008 Honda TRX450ER Sportrax 2008 Honda TRX450R Sportrax 2009 Honda TRX450ER Sportrax 2009 Honda TRX450R Sportrax 2012 Honda TRX450ER Sportrax 2013 Honda TRX450ER Sportrax 2014 Honda TRX450ER Sportrax ***Stock gearing for 2004-2005 models is 14/38 and 2006-2014 models is 13/38***