'Ehle' 'active' Active Carbon. When smoke passes through an activated carbon filter, a large portion of the harmful tars in the smoke sticks to the activated charbon. This makes the smoke pleasantly smooth without affecting the quality of the buzz.'Ehle' activated carbon filter systems removes harmful substances.This premium Quality with high absorption improve the taste of the smoke and reduce the amount of tar that reaches your lungs. It keep your pipe clean longer and make harsh blends taste smoother. Also make it easier to smoke pure.