I thought it didn't leak when 1st got it, but I was wrong, seems to be leaking from the base, it is not bad, but everytime I unscrew from a mod, there is juice on the mod and on the bottom of the billow, it is not leaking from the air holes, it is from the base, I have tried using different oring on the fill screw and that didn't solve it, so not sure if coming from the air flow screws, fill hole or even 510 pin. I also added some cotton in the channels when changed out wicking, and that made no difference either, wish I could solve it, as it does vape damn well.