This hard plastic tube is meant to reside in the place of a balsa filter, for those who smoke 6mm Filtered pipes but don't use filters. It lessens the size of the draft hole from 6mm to 3mm. These are not needed in order to smoke Savinelli filtered pipes without a filter; however, they are an option for those smokers who prefer the draft hole to be a more standard, unfiltered size.
Savinelli 6mm Filter Adapter Insert
$1.00