SRK-12 is constructed of heavy-duty steel with fully enclosed side panels and front and rear rack rails. The side panels are also perforated for passive ventilation. The racks are mounted on four 3" (75mm) casters with lockable fronts that can handle a weight capacity of up to 300lb (450lb without casters). It comes with a blank, single-space panel. Finally, the unique steel support bar design allows these racks to be compatible with either U.S. or European thread sizes, with both sets of screws included. Features: 21-space rack (99.695cm [109.855cm with casters] x 50.8cm x 45.72cm) Weight: 9.525 kg Heavy-duty steel construction with fully enclosed sides Front and rear rack rails Compatible with U.S. and European screw thread sizes U.S. and European rack screws included Blank, single-space blank panel 3” (75mm) locking casters for easy transport and fixed installation 136Kg (with casters), 204Kg (without casters) of weight capacity Side perforations for passive ventilation Black brushed, anodized finish Compatible accessories (sold separately) include Samson SRK Rack Drawers and SRK Rack Shelves