First and Foremost, hello all! I am excited about not smoking anymore and having been enjoying ecigs for 3 days now. I wanted to preface this question letting everyone know that I prefer pre-filled cartomizers as I do not want to go through the routine of filling my own for now. I have looked and found three threads that mention this brand. I recently called them after purchasing one of their starter kits to find out what battery they are using. They told me that they refer to it as an M40, it doesn't have a manual button which leads me to believe that its an M401. The other three threads I found referencing the Zerocig kit looks as though people just sent them back. Their mini battery is tiny and part of the reason that I bought this brand. It literally is the size of a standard Winston with the Cartomizer, granted it doesn't last as long but it feels comfortable in the hand. So my questions are is there a M40 versus an M401 or M402? What other brands of Cartomizers are compatible with this size battery if any? Thank you all for any help you can give!