The SpeakerCraft SC-BT-12 12” (300mm) Boom Tomb In-Ground Subwoofer features a waterproof HDPE enclosures, made from the same material used in municipal water supply lines and includes a high-flow port design in which the port and canopy assembly spreads the moving air evenly in a 360-degree pattern, thereby reducing air turbulence and eliminating annoying port noise. The woofer magnet is located on the vented side of the enclosure, which allows it to be cooled by airflow in and out the enclosure, adding longevity to the motor structure. And the port assembly is covered by an aluminum mesh grille that allows unrestricted airflow yet prevents intrusion of bugs, animals and debris.