Oh, the many, many uses of this humble little tray. You can rack two Speck ASC units (with or without transformers, although we personally prefer the version with), three FMR Audio units in any combination, possibly (but not tested) three Apogee Mini Series units and probably loads of other equipment we don't sell. What it won't fit? Any equipment that does not have holes on the bottom specifically to be used for attaching it with a screw. Our warranty covered the rack, but does not cover dumb-ass moves you might make with your other equipment. Please do not just jam a screw up in there, you might damage the unit.