Thunder Marine subwoofers are designed to withstand almost anything Mother Nature can throw at them. Featuring weather resistant polypropylene cones these subwoofers are extremely mositure resistant. Each subwoofers utilizes a sealed PVC basket to ensure moisture is kept out of the motor structure and an ASA plastic grille that is both impact and UV resistant. All hardware is either stainless steel or gold plated to protect against corrosion and maximize performance. These subwoofers are also infinite baffle capable, meaning they do not need an enclosure built specifically for them, they can use the hull of your boat as an enclosure so they can be mounted in many more places than a traditional subwoofer that would require an enclosure.