Yup. 37 inside, really just in case it pops. I bottle press flower and trim. It's more about how you prep and fill the bags then the mold. I just use my fingers and it's fine for 1/4 at a time at least. I use a rectangular mold for kief, squeeze it in that and slide into a bagAppreciate that my brother. So you're saying I should put the Kief in a 37 micron bag, before it goes in the 120? I also went ahead and bought a cylindrical pre-press mold, back when I was going to buy the Mini-NugSmasher. I still want to "bottle press," but aren't there some special cylinder shaped micron bags that I should buy also? Btw, thanks for helping a newbie out!