Stop replacing those constantly breaking glass downstems and give your water pipe a well-deserved upgrade with PieceMaker silicone stems! Available in a variety of colours that glow in the dark these stems fit 18mm openings, and provide a pop of colour to water pipes. Stop replacing those constantly breaking glass downstems and give your water pipe a well-deserved upgrade with PieceMaker silicone stems! Available in a variety of colours that glow in the dark these stems fit 18mm openings, and provide a pop of colour to water pipes. Downstem Features: Nearly Indestructible Built in Stainless Steel Bowl Included "Kap" for Travel Fits 18mm Openings