Reducer Glass Stems
Reducer glass bong downstems have two different sized joints, the larger one is a male joint and this is the part that is inserted in to the water pipe and the other is a smaller female joint and this is where your accessories such as a cone piece or ash-catcher etc. are inserted. The most common size for reducer stems is 18mm to 14mm where the 18mm joint is male and the 14mm joint is female. There are also 29mm to 18mm reducer stems where the 29mm joint is male and the 18mm joint is female, although they are much rarer.
If you need help selecting the correct length please view our "Downstem Measuring Guide" here.