Barely wider than a standard iPad, this is a perfect portable 2-octave controller that still manages to incorporate pitch bend and mod functions as well as sustain and octave up/down for the full range of notes. The nearly-flush key profiles are a slight adjustment over other key beds, but pressure sensitivity and aftertouch more than make up for that. Plus the keys are full-size, not mini.It is MIDI over USB only, but no separate powered hub is required for use with iOS devices.One caveat for those purchasing the blue model: the product image is misleading. The housing is not the solid blue shown, but rather a much lighter blue with a shimmery sheen to it. For me, that was a little disappointing, but not a deal breaker. This is a great controller for sketching out ideas or just perusing the sound banks of your synth apps.