The Kanger E-Smart clearomizer is a small, portable device with a 1.3ml capacity. These clearomizers have the popular 510 threading and a screw top mouthpiece. Their compact size makes this device very portable. With 510 threading, these are compatible with many 510 & Ego batteries on the market today. This clearomizer provides an outstanding throat hit, abundant vapor and good performance. Filling is a breeze. Simply unscrew the mouthpiece and fill the tank - it's that simple!