bombastinator, sorry for the slow response and thanks for your suggestion. The problem ended up being that the company I bought the Triple 28 from sent me one with a 4ml installed and a spare 4ml. I was totally confused with Vandyvape's description saying you could use 2ml/4ml but not giving any info about the silicone stopper. I phoned myvpro.com which is Vandy's U.S. customer service contact and they were trying to tell me that the 2 glass tanks were exactly the same, just remove one and put the other one in which made no sense, that's like saying a quart of milk is exactly the same as a gallon. Anyway, long story short, I went to a U.K. site and that's where I found out that I should have been sent an RTA with a 2ml installed and a spare 4ml that way I would have gotten the stopper I needed. I think if Vandy is going to sell these RTA's in 2 different versions they should be a lot more clear with their item descriptions. Thanks again for you reply.