This Oregon 77-305-1 spark plug is a resistor plug that fits Briggs & Stratton, & Tecumseh. Oregon replacement parts are built to meet or exceed OEM standards. Replacement Spark Plug for Champion RJ19LM, Bosch WR11E0 & NGK BR2LM These have been designed for chainsaw, brushcutter & lawn mower applications, & it is not recommended that they are used elsewhere. Additional antivibration features include: a steel wire terminal pin & locked terminal nuts, to ensure efficient connection even in extreme conditions.