Good Ventilation: This 12" Deep Steel Shelf with Ventilated Design Maximizes Air Circulation and Keep your AV or Other Equipments Cool. Product Size after Assembly: High 1U x Wide 19" x Deep 12" (30.5 cm); 1U Tray Usage Size: W 17.2" * D 11.9"( 43.7 *30.2 cm) Compability with: Fitting any Standard 19" Server Racks or Cabinets to Hold your IT, Data, AV, Network Equipments, or Other Non-rack Mount Equipments. Durable: This 19-Inch 1U Server Vented Shelf is Made of High-quality Cold Rolled Steel with Powder Coated Finish. Make the 12" Rack Tray Durable. Max. Loading Capacity: 30 lbs. Easy Assembly: Only Need to Assemble the Side Brackets onto the 1U Rack Shelf. Including Screw for Assembly and M6 Screws & Cage Nuts for a Quick Install. Lip Upwards or Downwards: When the lip is upward, this 1U shelf backstop to keep your gear secured. The lip can be upwards or downwards according to your different usage.