Further Details Constructed of 12-gauge cold-rolled steel. Four-post stability. Open design provides maximum ventilation. M6 mounting. Shipped unassembled. Assembly hardware and mounting hardware are included. EIA 310-D compliant. Also available in 15U, 37U, 42U, 51U, and 58U. With solid four-post construction in a standard rack size at a very economical price, 4-Post Racks from Black Box are data center staples! Our 4-Post Rack combines the stability of a cabinet with the airflow of an open rack. It''s tough, too-its 12-gauge steel, quality construction supports more than a ton of equipment! The rack ships unassembled for easy transport to your site. Assembly is simple with the included hardware. You can install it as a standalone rack or bay it. To bay the rack, use our Baying Kit (RM7002-R2). The rack conforms to the EIA standard for 19" equipment mounting and features universal M6 mounting holes. It comes with 50 M6 cage nuts and screws for mounting.