E3.10 Diamond Fire Small Engine Spark Plug. Lifetime Guarantee. For All 2-16 HP 4 Cycle Small Engines.Replaces Champion 5861, J17LM, RJ17LM, J19LM, RJ19LM; Replaces NGK B2LM, BR2LM, B4LM; Replaces Autolite 458, SE458, 456 14mm Thread Diameter, .375" Reach, 13/16" Hex.