Quick Facts Flanged for extra strength. Offers 68% open area. Constructed of 16-gauge perforated steel. Black, powder-coat finish. Guaranteed for life! . Manufacturer: Black Box Corporation. Manufacturer Part Number: RMT946. Brand Name: Black Box. Product Model: RMT946. Product Name: Vent Panel, 2U (3.5"H). Product Type: Vent Panel. [Physical Characteristics] Color: Black. Material: Steel. Compatible Rack Height: 2U. Height: 3.5". [Warranty] Limited Warranty: Lifetime.