M-AUDIO 61-key MIDI keyboard with volume adjustment and modulation functions. - Model Name: KEYSTATION 61ES - Brand: M-AUDIO - Features: Volume adjustment knob, modulation wheel - Number of Keys: 61 keys Operation has been confirmed, but as you can see, the keys are yellowed due to aging. I checked used listings for the same product and found that they are similarly yellowed, so it doesn't seem like the item was poorly maintained. Thank you for looking. Due to decluttering, [Will be disposed of if NOT SOLD by May 17th]