| 摘要 |
<p>With improved tar retention, having a filter mass arranged over the whole cross section of a smoke channel in which a throat is provided in front of the filter mass at the side opposite to the material being smoked, formed from a cylindrical bush terminating shortly before the filter mass, the throat taking the form of a frustroconical surface of 40-80 degrees cone angle, merging at its narrow end into the cylindrical bush, which has a length of at least 2mm and internal diameter of 1.5-2.5mm.</p> |
