Five heights available: 6U, 9U, 12U, 15U and 18U (1U = 44.45mm) Width: 600mm nominal (actual width 557mm) 600mm wide = standard 19" mounting (600mm nominal - actual width 516mm) Depth: 500mm nominal (actual width 525mm) A wall mounted back section, which is not visible when the unit is closed, for 19-inch mounted interconnection and is concealed within the front equipment section. Full 900 opening of front equipment section Easily demountable front section via spring loaded retaining pins A single keylock secures the front section to the back section of these boxes Glass door, MaxiVent door or Plain door - supplied with cylindrical lock