The NGK DR8EIX Iridium IX ATV spark plug for Yamaha YFM400 Fh Big Bear Realtree X-Tra 4X4 USA 2001-2002 ensures long-lasting performance and maximum ignition efficiency. Its ultra-thin iridium center electrode delivers powerful combustion and improved fuel economy. Designed for modern high-performance ATVs, it offers fast throttle response and excellent durability.