Midnight Glass Clear Dry Ash Catcher 18mmMidnight Glass Dry Ash Catcher. This simple, clear dry ash catcher is the perfect minimal ash catcher to add to your bong to help keep it cleaner. With no percs and a small lightweight design, you can easily use this on small bongs or large bongs. Add a small layer of water to the bottom and all the ash that pulls through will stick, Keeping your bong cleaner!