Renthal Front Chainwheels are simply the finest front chain wheel on the market today. Front Chainwheels feature specially developed Nickel-Chrome-Molybdenum steel which is case hardened and core refined to give the ultimate combination of strength and hardness. Feature self-cleaning mud grooves between every tooth on both sides help prevent dirt build up. Precision CNC Machined to extremely tight tolerances. Fits: Yamaha YZ 125 2005-2013, WR 250F 2001-2012, YZ 250F 2001-2013; Gas Gas ECF250F 2013, ECF300F 2013