The MT3S is a new design from the First MT3. Kanger has intergrated the same design they currently use for their eVod & Protank which in our opinion is the best one on the market to date. This Clearomizer holds 2.4 ML of e-liquid with replaceable coils heads like the eVod in which makes the replacement coils a little cheaper. The MT3S works on the Ego style batteries by using the ego cone threads instead of the 510 threads. As far as mods go some will require a 510 to ego adaptor.