JL Audio M7 Marine Subwoofer Grille - King of Bass.With oversized, overbuilt components and very powerful motor systems, M7s are extreme subwoofers optimized for high-power operation in open-air applications. One marine subwoofer; One grille; Six stainless steel mounting screws; Six stainless steel washers; Generates Stunning Bass In Open-Air; Engineered for use without a dedicated enclosure; Grille and Trim Ring are easliy removeable for painting; Exceeds International standards for salt fog and UV Exposure; Manufacturer 3 Year Warranty;