Middle Atlantic MD-48 studio desk with (2) MB-6 Tiers. Each tier has (2) 6 space racks for a total of 24 rack spaces. Heavy-duty hinged fold-able steel base with 1" main work surface and (2) 1" upper tiers. Very solid. Good condition with a few scratches. Attached photo and drawings show how the 1st and 2nd upper tiers are attached.