Sizes of Bong Downstems
When it comes to finding a bong downstem things can become a little confusing and annoying if the bong seller did not include the sizes needed for the downstem replacement. There are two different sizes of your bong that you will need to measure, first of all lets take the easiest measure which is the length. Now your glass downpipe has a sanded part which locks into the bong, this is known as a glass on glass joint. You will measure from the top of this joint to the very bottom of the downstem, this is how you determine the length.
Now you need the diameter of the downpipe joint, the standard sizes are as follows; 10, 14.5, 18.8 and 29.2 (all sizes are in mm). You can simply use a tape measure on your bongs socket to get this size, but remember you will need to find out what your bowls joint diameter is too.
Downpipe Size Guide for Bongs
That's it! If you have troubles I suggest you contact the bong seller and ask them to help you pick a replacement. There are some pretty fancy options when finding your replacement, you could also check out the diffuser downpipes.