Rockville RW7SV13 13" Vented JL Audio 13W7 13W7AE Subwoofer Enclosure Sub Box Single 13" 3.1 cu. ft. MDF Vented/Ported Subwoofer Enclosure Box Specifically Designed For The JL W7 or Similar 13" Subs. Machine precision cut mounting holes USA Heavy Duty MDF Construction. Top of the line Glue for extra durable adhesion High quality GOLD spring loaded terminals. Designed, tested, and engineered to work with most of todays popular woofers. These enclosures are built with the quality additives needed to maximize the performance of any sound system.