Stage, install, or transport up to 3U of rackmount equipment with a 20-inch rail-to-rail depth. The SKB 3I-M3U20-FRM provides threaded steel rack rails at both the front and rear, giving equipment support at both mounting ears and accommodating hardware that requires rear fastening. Its open-frame construction keeps connectors, power supplies, and rear-panel controls accessible during installation and service. Injection-molded top and bottom sections form the structure around the rack rails. Rubber feet on the frame support stable placement on a work surface and allow compatible frames to be stacked for modular equipment layouts. The 20 x 20 x 7.6 inch exterior dimensions make this frame suited to equipment staging where a shallow, enclosed rack case is not required. This is a rack frame rather than a sealed transport case: it has no lid, gasket, padding, shock protection, wheels, or closure hardware. That distinction suits studio equipment installations, bench integration, and pre-racked gear assemblies that need fast physical access. Rack screws with 10-32 threads are included, so compatible 3U equipment can be secured directly to the threaded rails without separately sourcing basic mounting hardware.