From design to delivery Atrend products are tested vigorously to ensure sound quality and accurate engineering. Working with only the latest in computer automated software and machinery Atrend continues to be a trend setter in the marketplace. Atrend delivers quality results by utilizing only the most efficient engineering and manufacturing processes. 12 Single Vented Subwoofer Enclosure. Carbon Fiber Painted Finish. Ultra plush black carpeting. Silver spring loaded terminal cups. 3/4 MDF construction. Completely Miter and Dado panel. Total box volume: 1.75 cubic feet.