I second the goblin mini V3, it's a great atty, dual and single coil, easy to build, never leaked on me. It also can be enlarged to 4ml with an extender. One of my best tanks.
Onyl thing to be aware of when using with a Pico: when screwing on te atty you need to remove the battery cap, as it is topfill you won't be removing the atty that much so it's fine with me. I use it all the time on the Pico....
Onyl thing to be aware of when using with a Pico: when screwing on te atty you need to remove the battery cap, as it is topfill you won't be removing the atty that much so it's fine with me. I use it all the time on the Pico....