Evo-D Tanks are very popular right now. Great taste and low cost is the obvious reason for this. BCC(Bottom Coil Clearomizers) utilize a short wick design to feed the coil. This design has made great strides lately. The older versions were kind of unreliable and suffered from over saturation and poor quality. I can attest personally to the new standards of this tank, as I use them daily. BCC Evo-D tanks are an awesome purchase!!