rba tank systems that I love and work great for me are: flash-e-vapor V2, Rose V2, Aqua, Russian, Taifun GT & GS. All in full metal jacket SS tanks. Hold anywhere form 3-5.5 ml of juice. I usually take 3 mods w/tanks to work, so have plenty of juice and power to make it through the day. Use both mechs and high amp regulated mods.