These subwoofer boxes are made with pride in our own facility here at HiFiSoundConnection. They are constructed with the highest quality MDF that meets our rigid standards. Unlike our competitors we do not use pressed cardboard or rice wood materials from overseas. All Boxes feature high grade spring loaded terminal cup(s) for the absolute best connection possible. All of the custom series enclosures are made to fit precisely into your vehicle to the get the max performance from every extra inch of wasted space.