The Niles NI-GSBSUB-12 12"In-Ground Subwoofer features a waterproof HDPE enclosure which is dunk tested before shipment to ensure against leaks. The port and canopy assembly is designed to move air in an even 360-degree pattern, while the woofer magnet is placed on the vented side of the enclosure to leverage woofer-cooling airflow for motor structure longevity. The critter-proof aluminum mesh grill cover allows for maximum air flow while protecting the entire port assembly against bugs, animals and debris.