I started out with an epen can't remember the name that petered out after about a month about a year later I went in for surgery and I knew I would be there about a week so I picked it up again and it didn't take long to get frustrated with dead batteries and juice leaks, so I bought a kanger kbox mini it worked pretty good but the tanks always leaked. So i bought an innokin crios tank and the damned thing wouldn't work. So I did a supid and put a copper patch in it to make contact which killed the kanger. So I bought a Smok T-priv and after figuring out how to make it work, I am now a happy vaping fool. I went from a pack a day to 6 cigarettes a day in two days. I am loving it.