Chain & Sprocket Kit Contents: 14T Front Sprocket - SPF43814C 50T Rear Sprocket - SPR27050C 114 Link RK Chain - RKP520KZX114 RK Kit Box - SPRKITBOXRK chain and sprocket kits are the perfect drive maintenance kit for your bike including a strong and durable 14T 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 Heavy Duty 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:A heavy duty non-ring chain designed specifically for road bikes as a lightweight alternative to your standard heavy duty chains the KZ series has a chromoly steel construction with seamless rollers and bushings with oversized special alloy pins for added strength. Excellent quality and cost performance for 125-250cc road bikes. Fits: Yamaha WR400F 1999-2001 WR426F 2001-2002 WR450F 2003-2007 2009 2011-2021 WR450FSP 2021 YZ250 1999-2001 2005-2008 2011-2015 2017-2020