Replacing and adjusting the spark plug gap on our Beckett AFG oil burner has always been a fiddling nightmare, measuring 100 times and still having to readjust multiple times before we it get them set right. We too were afraid of this process. I put this Beckett probe on my wife and used it to attach our latest set of electrodes. She was happy when the stove ignited properly for the first time without any further adjustments. Now she thinks I'm an oven god, and that's a good thing. In my opinion the best piece of plastic ever made by man - without which I will not install or replace electrodes.