Two rivers is the place to go, it might not be the biggest or has the most hype but they take care of their people. I had a issue with a bunch of zen Cartages the 1mg wouldn't work on my pen but the half mg's would so they thought maybe it was the pen but they tested the pen right in front of me and the pen was fine. They gave me two half grams for every gram I had and their was lots and two O.pen 1mgs also didn't work that they replaced with something else because they had no more O.pens. Thank you two rivers..... Misty