B8EG (6103309) NGK Racing Spark Plugs have been designed to withstand the rigours of racing applications. Tuned, racing-engines are often subjected to speeds in excess of 15,000rpm during races which means that temperature, pressure, vibrations and currents in the conbustion chamber are so extreme that conventional earth electrodes could break or melt. NGK Racing Spark Plugs are designed with a ring-shaped earth electrode which means that the spark creeps from the middle electrode to the earth electrode instead of jumping. To Fit- GAS GAS ec 250 1997 - HUSQVARNA 250 WR 1999 - HUSQVARNA 360 WR 1998- 2000 HUSQVARNA 360 WXC 1998- HUSQVARNA WR 360 2001- YAMAHA IT 250 4V5 1981 - YAMAHA WR 250 Z / ZE / ZF 4JW 1993 - YAMAHA YZ 250 1984 - 1994 YAMAHA YZ 250 4MX 1995 - YAMAHA YZ 250 F 1994 -