This is a printable bong with either a 9 mm hole or a 14.5 mm hole depending on the bowl you want to use. Tell me in the comments if you need a different size or message me on my profile. This will print without problem as long as you use supports but only touching the bed. You do not need, nor want, to deal with the headache of removing all the supports from the inside of your new bong. I recommend using a food safe plastic which you can wash out with isopropyl alcohol, however this is only a guess do your own research before smoking anything through a potentially toxic plastic! i used PLA not my favorite choice but my only choice from what i had, ABS will leave an off taste and is not safe to my understanding, please correct me in the comments if i am wrong. Ckcarr3 and i are at currently testing and designing an update to this bong so all pieces that include threading are entirely experimental at the moment.Print with supports only touching the bed, you do not need to have supports on the inside of your bong they will be next to impossible to remove and help you in no way.