Chainsaw Repair

So, E is standard reach whereas F is extended reach?  Kinda like a Champion CJ-6 vs CJ-6Y?  Also looks like there is a dab of Iridium on the F electrode.

I wonder about those rounded corners on the Iridium ignitors.  Way back in Lawn Boy ignition school, we were taught that a spark plug with a (worn out) rounded ignitor took twice the voltage to fire over the sharp corner of a new plug ignitor.