Glass dry/ash catcher with chamber screen stops any rogue ash from entering into your main piece.  Light weight with a flat base they can be left on your rig or stand alone on a flat surface.  Theyre small enough to put onto most waterpipes and big enough to catch a sesh worth of ash without the need to clean in between.  The design does not water filter the smoke at all, the piece only serves to stop the ash from entering your main piece.  If the chamber is filed above the inbuilt glass screen, it will percolate but not without pulling a heap of water into your main piece.  For this reason we recommend filling below the in-built screen and using the water only to extinguish and collect your ash.