Ok now... These are treats Puch Hobbit heads. The one on the left is the 47.6 Athena head. This one has a reasonable mods. The deepest part of the head is nowhere as deep as the right one which is the 46 mm mild one and not to sound to much like Donald Trump but it's an embarrassment that treats when told that over three mm of the standard b6hs stick out and the heat transfer reliably fouls the plug they told me I was obviously in error. . Well it is a pos that I will not sell anyone and why should I be so nice when I asked them to get this out of my life I got lip only. But the other one isn't as severe and faulty machining down so only a mm sticks out and I think it will run perfect if on the Athena. I'm holding onto my modded metrakit head. I drilled both out to m7 and they will slip on just fine. Let me know if u want the left one. Right is not for human use. Sorry Benji but when I contact treats to tell them something isn't right u Betta believe it. I've been at this for a while now. Oh putting a copper washer to make the plug flush. Right ....doesn't work. Too much heat. Spark plugs are designed with the metal around it in mind ... I am in a bit of a foul mood. Must be the heat.