This is absolutely the best filter box on the market. It is manufactured in America in the state of Virginia. Its compact size allows it to be mounted easily. It measures 10 1/4" x10 1/4", and the box itself is 6 1/4" wide. It has two 8" round collars that are sealed to the box. From collar edge to collar edge, it's 13" and weighs 5 pounds. It utilizes a 10"x10"x1" inch filter. Which is commonly sold in stores and online and very reasonably priced. It has a spot welded track on all 4 sides to support the filter. This filter track also prevents air from being able to flow around the filter area, increasing air filtration. The filter track and the round collars are sealed also. The door is gasketed to prevent air leaks and uses 4 magnets to secure it in place. The round collars are crimped to allow you to easily hook it up to your ductwork. It comes with one 10"x10" merv-13 filter, mounting brackets, and screws for installation. Compare this filter box to any other filter box in the market, and you can  see why this one is the best. Others don't  have complete filter tracks, so the air isn't completely filtered. Others don't supply mounting brackets or screws for installation. This is the box you want and need to provide proper air filtration.