I got my Serpent Mini today. I was disappointed that an Allen wrench didn't come with it, and the one I have for another RTA I have is too small. I discovered that the smallest flat head precision screw driver I have will work temporarily, so that saved more curses coming from my mouth . I used one of the coils that come with it, so also temporarily I'm sub-ohming. Tonight after I put the kids to bed I'll build my own coil. According to the Steam Engine calc, 10 wraps of 26g with a 4mm ID will give me the resistance I prefer, 1.8 oHms. If that coil fits in, I might try an extra wrap or two..