If the standard cooling and filtration from your bong just isn't enough, or if you are fed up of constantly cleaning ash out of the base of your bong then you need an ashcatcher/pre-cooler. These sick catchers from Grav Labs not only catch all your ash, keeping your bong shiny and clean, but they also have a trio of forced stacked percs built in which combine with the 8 slot diffuser in the downstem to make this one of the most efficient pre-coolers around.