This is the Gator GRB-4U. A part of their Rack Bags Range. It is a Rack Bag; Nylon Over Plywood Construction; 4U. Portable Lightweight Rack with Close-Grained 9mm Plywood Cabinets Covered in Padded 600-Denier Nylon. Features include - Threaded Rail & Zip-Out Flaps, Large outside accessory pockets, Heavy-duty shoulder strap, and Two padded carrying straps.