Glass Collar Adapter 18mm to 14mm
This air tight glass collar adaptor will allow you use use any of the 14mm male cone pieces GBA sells with any bong or joint that would typically require a 18mm male cone piece.
Basically, this adapter will make the stem joint narrower. 14mm is the most common size cone piece sold globally so this adapter will come in useful more often than you may think. It will also allow you to use any of our tar catchers with your 18mm stems.
If you are unsure, or would like to check if this product is what you need for your setup, please do not hesitate to ask.