Hi everyone. I have been smoking on and off for over 16 years now and am now really getting into the bong scene. I have hit bongs when I was a teenager but boy have times change! I bought a 14" ice notched Roor. In hindsight I should of went for one with some percs but it will do. My issue now is that I got a 11 arm ash catcher and a glass on glass bowl but now have change my downstem. I wanted to go with a 6 arm diffuser but the whole 18 to 14 mm confuses me. I purchased this: http://www.ebay.com/itm/271615045684 and this: http://www.ebay.com/itm/111274309635 Will a diffuser that says 18mm to 14mm like this: http://www.ebay.com/itm/331263772144 work with something like this: http://www.smokeday.com/12-pipe-bong-assorted-logos.html I'll attach the pictures of my downstem.
The picture of the downstem you posted isn't glass on glass so it won't work with Roor or anything that you posted otherwise. What size joint does your bong have? Put a dime up to the joint side- if around half of it fits, it's 18mm. That will determine what size downstem you need. In term, the joint size of your downstem will determine the size of the ashcatcher you need. Make sure you get the correct length downstem- measure the existing one. Too long and it won't fit in and too short, there will be too much water.