Replace or upgrade your worn chain and sprockets with this market leading sprocket kit featuring quality JT Sprockets and D.I.D chain brought to you by THS Moto. Note the chain may need to be adjusted to length using a chain breaker tool. This Sprocket Kit contains a 14 tooth front JT sprocket and 50 tooth rear JT sprocket with a 520V114 114-Link 520VO O-Ring solid bush clip link DID Chain Fits: Yamaha WR450F 2003-2006 2012-2013 YZ250 1999-2001 2005-2021