This product, which marks all Savinelli pipes, is a filtering system based on balsa wood properties. Its main feature is the natural (without additives or chemical materials) absorption of humidity and that annoying drizzle which is created inside the shank. It also ensures a smaller scale and therefore a better cleaning. This power of absorption comes from the numerous and pouros balsa fibers which guarantee a perfect smoke without altering the tobacco fragance and aroma. This is a 6mm balsa, suitable for pipes with this diametre