DiamondFire E3.16 Small Engine Spark Plug Replacement Spark Plug 14 mm thread diameter; .307" reach; 5/8" hex socket Designed to increase horsepower, lower emissions and increase fuel efficiency up to 13% Quicker starts; saves on fuel Replaces Champion DJ6J, RDJ6J, DJ7J, RDJ7J, DJ7Y, DJ8J, RDJ8J, 5847, 5851; Replaces NGK VMGF, BMR6F, BPM6F, BPMR6F, BM7F, BMR7F; Replaces Autolite 2554, SE2554, 2956, SE2954, SE2956 Lifetime guarantee Replacement spark plug Fits several smaller engines and is designed to increase horsepower and lower emissions Replaces Champion models DJ6J, RDJ6J, DJ7J, RDJ7J, DJ7Y, DJ8J, RDJ8J, 5847, and 5851; Replaces models NGK VMGF, BMR6F, BPM6F, BPMR6F, BM7F, and BMR7F; Replaces Autolite models 2554, SE2554, 2956, SE2954, and SE2956 Quicker starts and innovative design increases fuel efficiency up to 13% Lifetime guarantee