I have several pieces that take the charcoal and cotton from a special designed bowl to a filter system for my 18mm beaker bongs or straight tubes. the best I can get is to clean bong and set in fridge for several hrs and then hit a clean slide bowl and its so good and to see how much is in the cotton after a day 2 the most whit how much I need to consume for its the only meds that make any difference in my horrible case of Crohns. VapeBros is a great company that has fast delivery and great prices on quality parts and vapes.. Keep up the great job..