The ceramic center rod is made out of a porous white glazed ceramic. A plastic ring constructed from polypropene sits down below the tank. There is certainly an o-ring created from a silica gel compound that helps seal the ceramic rod in the plastic ring at the base from https://buy-vape-carts-online-in39137.blogpixi.com/27066538/the-best-side-of-buy-vape-carts-online-reviews