A or B? octane plug

[Gunzi]

I've got an octane plug from an 2L 16v XE engine and rather than having 95 / 98 on it, it has A and B. Does anyone know which one is for the higher octane rating (98)???
cheers
gunzi

[Ste_Nova]

it's not an octane plug... its a noise plug.... leave it on A

[Gunzi]

Cheers!!