If you have a vision grand, try this. Take a pull. Now, remove the mouth piece and give it another try. If yours is anything like mine, you just got a better hit and flavor. I'm not sure why but there is clearly a difference with mine. So, I made a new mouth piece out of delrin that goes all the way down to the stopper and has a hole just big enough to go over the tube part of the silicon stopper and it is a much better vape. YMMV.