Compatible with many snowthrower and tractor engines. E3 Spark Plugs feature DiamondFire technology. A revolutionary new spark plug that provides more energy, greater efficiency, and is more eco-friendly. Designed to increase horsepower and lower emissions. Quicker starts, saves on fuel. Replaces Champion RN4C,N4C,RN7YC. Replaces NGK B6ES, BR7ES, B7EB, B7EB11, and many others.