I have an 18 gauge internally threaded Industrial Strength bar in my philtrum piercing and am looking to spice-up the dermal end, but have had a lot of trouble finding tops that fit. I've deduced via trial and error that the threading of my existing jewelry is 0.9mm, and that ends sized 18g-16g (universal sizing of some kind for those two gauges?) are somehow larger than 0.9mm do not fit my 18g IS bar.

I really love this Anatometal dermal end: http://www.steelnavel.com/product.asp?ID=6387 and see that both 18g and 16g are listed as separate buying options...is the 18g 0.9mm threading? I see Anatometal tops for sale elsewhere that are listed as "18g-16g" and am concerned that the 18g one listed won't fit because it's actually the same threading as the 16g.

This item is a little on the pricey side, I'd love a second opinion! Thanks!!