The alm rn9yc spark plug is suitable for most honda and mac allister lawnmowers and many other engines it compares to bosch wr7dcchampion n9yc rn9ycdenso lr15ycngk bp6es bpr6esoregon olr15ycrocwood f6rtctorch f6tc note alm rn9yc is printed with alm 9 on the spark plug