So I received my TFV4 a few days ago, I've read about the orings being of poor quality so I was pretty happy to find two spare included, however, I can't for the life of me figure out where they go, I've pulled the one out that seals against the glass at the top of the tank and it's just a normal black oring, as you can see, the spares seem to have a lip on them, any ideas ? I'm waiting for my mod in the post so I have a day or two to play around with it before I fill it. Thanks