The first thing to say, which is of course pretty obvious to serious smokers, is that the downpipe is an essential part of the bong and having a spare to hand is a wise decision. As an owner of a ROOR bong you will be fully aware that you have an item of quality, which all began over two decades ago by German glassblower Martin Birzle.
To ensure that you have the correct one for your bong, please ensure that you measure it correctly and to do this you should firstly check the gauge of which there are two, this will be either14.5mm or 18.8mm across, the same would apply if you had to buy a new bowl.
Next check out the stem length and to do this you should measure from the top of the misted section of glass to the bottom of the stem. If you are in any doubt we would suggest that a stem that is a bit short is better than one that is slightly too long. The reason being that if the base of the stem touches the base of the bong the misted sections will not make an airtight connection. To give you one example the ROOR 250 downpipe uses a 14.5mm gauge 10.5cm stem.
The items made by ROOR are of exceptional quality and as with anything damage can occur, so having spare to hand will save you frustration when all you want is a nice peaceful and quiet smoke.