I have been using madvapes for supplies and batteries for my box mods for about 2 or 3 weeks now, and had a question regarding fully assembled mods that they sell. I notice they have a VV for just under 40 I believe, but I would want a voltage indicator on there some where so that I would know what voltage I was vaping with. Do they do request for an additional charge, or would that be something I would have to add myself after the fact?