Roland 49-key MIDI Keyboard Controller, black (A-500PRO-R) Inspiring feel and response for serious players Velocity-sensitive 49 keys with channel after touch 45 assignable controls: knobs, sliders, buttons, transport and more USB Bus Powered - no AC adaptor required (AC adaptor is an optional) 8 Dynamic Pads for finger drumming and MIDI triggering Works with any DAW on Mac or PC (Supports Windows 7 and Mac OS X Snow Leopard) Durable Roland-quality manufacturing and craftsmanship Sure-grip Pitch Bend/Modulation Stick Expand playability with sustain and expression pedals (available separately)