Chain & Sprocket Kit Contents: 13T Front Sprocket - SPF124813C 50T Rear Sprocket - SPR89950C 120 Link RK Chain - RKPGB520MXUX120 RK Kit Box - SPRKITBOX RK chain and sprocket kits are the perfect drive maintenance kit for your bike, including a strong and durable 13T front and 50T rear steel sprocket, constructed from SCM420 chromoly steel alloy (front) & C45 high carbon steel with a electroplated Zinc finish (rear) paired with a high-quality UW-ring RK chain this kit has everything you need to replace your old warped and stretched chain and sprockets. The perfect alternative to expensive OEM replacements while designed to meet and exceed OEM specifications. Supplied in presentable packaging with a carry handle for convenient transportation. About the Chain: Featuring RK's Ultra Thin Seal technology, the seal thickness of the MXU series UW-rings are less than 50% of the common seal. Made for professional enduro/motocross racers. The UW-rings significantly improve chain life by lowering friction over your conventional heavy duty chain, while the ultra thin seals reduce weight compared to a O or X-ring chain. Fits: KTM 125 SX 1998-2005 2007-2015 2017-2019 150 SX 2009-2012 2014-2019 150 XC 2014-2015 150 XCW 2017-2019 250 EXC SIX DAYS 2015-2017 250 SX 2004-2009 250 XC 2016-2019 300 EXC 1998-2004 2006 2008-2011 300 EXCE 2008-2013 300 XC TPI 2020 300 XCW 2010-2016 350 EXCF 2012-2019 350 EXCF SIX DAYS 2015-2019 450 EXC 2003-2006 2008-2012