It is 510 threaded not ego as in, it does not thread on the skirt portion. It is ego "fitted" to cover the outer threading where you would normally mount a cone. I've been vaping for less than a year and have tried many things that were hit or miss. I have a cabinet full of functioning vaping stuff that just goes to waste because they don't perform.
I kind of stumbled on these mega shorty dual coil cartos looking for ANYTHING to try. Just so happened to be from one of their close friends in the business and they far surpassed my expectations. For awhile I was stuck on the clearos and I do like them, but got tired of the cleaning and the leaks. Plus with most clearos, nanos and tanks, if you don't keep them (near) full they dry hit and/or burn so what's the point of all that extra fluid capacity. So I thought what the heck back to cartos...so simple. But these, wow these work so well.
My "medicine" cabinet full of wasted money with trial and error hah. Most stuff I just threw away if it was absolute garbage.
and...
http://www.e-cigarette-forum.com/fo...stion-box-feedback-thread-83.html#post7950770
This is one fitted on an x2 900 with an adapter and one fully seated on an ego.