Matrix Perc Dropdown Ashcatcher - 14mm 90° - Plain Jane Glass A functional accessory from Plain Jane Glass. This multi-arm ashcatcher will add an extra level of filtration and percolation to your pieces with a matrix percolator. Pick up an ashcatcher if you are worried about protecting the investment you''ve made on your favourite bong or expensive piece. It will keep your bong cleaner and allow it to hit better.