Our 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. Using top quality MDF makes the enclosure much more rigid and gives your subwoofer a great platform to perform at its best. This makes our boxes a little more expensive but you truly do get what you pay for. Our boxes are made from precision cuts of MDF. They are then liquid nailed, nailed and completely sealed. We then wrap them with high quality carpet that matches most vehicle interiors. All Boxes feature high grade spring loaded terminal cup(s) for the absolute best connection possible. All the custom series enclosures are made to fit precisely into your 02-09 Chevy Trailblzaer / GMC Envoy to the get the max performance from every extra inch of wasted space. We guarantee you will not only see a difference in the quality of the boxes we build, but you will hear the difference and that is what is it is truly all about.