Build a Custom Bong Have you ever thought "I have the perfect idea for a bong!" but couldn't find the right combination of percs or other features? Your wait is over! With the new Build-a-Bong tool, you can customize your perfect piece! Have fun with it! All the parts for collecting the bong are on my page. This is the the thread that connects the parts of the bong Dimensions of this part: 45mm./45mm./28mm. Dimensions of the complete bong (if one middle part): 130mm./125mm./360mm. For all questions - write.