VaporCone Elite is the vape pen im talking about specifically, but from what I understand the filled THC Oil cartridges that you can purchase, fit multiple models. I got a filled cartridge that has measurements on the side in ml so you can tell how much you have left. Well the measurements start at 1.6, but when I actually opened it and checked, it was only at 1.4ml. Anyone have experience buying these on the regular, and can tell me if they are always short? Are they really interchangeable? Also what do the filled cartridges typically run at a store?