i tossed my bong years ago......it was a three footer...convertible to six. There is a story behind it;
Back in college, me and my roomy decide to build a bong. Since we didn't have the means to work glass, we hatched a plan to procure some suitable acyrlic tubing.
I found a supply house that had chemical and heat resistant clear acyrlic tubing and told them we needed a couple scrap lengths for a physics project demonstrating Bernouli's equation. They agreed to provide some in the name of higher education(YES!).
A couple trips to Lowes for plumbing and we were in business...........a 3footer......that could be augmented with another 3 foot section for parties.
It was dubbed "Homer" because a rubber Homer Simpson head adorned the top of the tube.
those were the days......I think.