The Promethius is a genesis style tank if I'm not mistaken. This means that the deck for the coil is on the top of the device. You mount the coil in top, and extend the wicking down into the tank below. I had a Kraken clone that was a similar set up. These are usually wicked with stainless steel mesh, however you can use cotton if you are so inclined. Unless wicked with stainless steel just right, you may have to tilt the topper in order to juice your coil. Some people don't like to do this. Also, because of the deck being on top, these are more prone to leaking when left on their sides. If you get good enough at it, you can avoid this though. I just gave up and went for the Kayfun style clones. The Fogger is kind of like a Kayfun, with the deck and coil on the bottom.