Check the listing for details. Korg microKEY Air-25 25-key Bluetooth Keyboard Controller. Condition: New. Listed at 167.98 USD. It just doesn't get more portable than the 25-key Korg microKEY Air MIDI controller keyboard. Grab your laptop or mobile device, pick up your microKEY Air, and you're all set - you don't even need to remember to pack a USB cable! A first among the cool MIDI keyboards we've seen at Sweetwater, this Bluetooth-equipped controller can connect wirelessly to your computer or mobile device, providing you with about 30 hours of low-latency virtual instrument control with just a pair of AA batteries. Sure, you can run it off of USB and even power it from your iPhone or iPad, but you don't have to. There's a cool pitch/mod joystick onboard, as well as a sustain button for holding notes, and the 25-key microKEY Air comes complete with an awesome software package too.