Brass pipe screens to fit most bowls. Pack of 5 mesh gauzes, which sit in the bottom of your pipe ensuring the Tobacco is kept away from any moisture lurking the base of your bowl. This makes your Tobacco go further, burn cleaner and taste better. You also get substantially less soggy waste in the base of the bowl
These last a fairly long time but eventually get clogged up and wear, simply empty into the bin and replace!