1. changeable coil 2.bottom heating 3.good quality ego atomizer 4. cheap price on ... Evod atomizer is built up with 4 parts: coil unit, bottom screw , tuberight now you just need to change the coil ... unit not the whole bottom coil , it would save you half of cost.one evod ... atomizers,USB+adapter, user manual, kitbox evod changeable coil and bottom heating atomizer