This is a 25-key MIDI keyboard that connects via USB and also supports Bluetooth. I purchased it new and have only used it a few times. The body has some minor dirt, scratches, and signs of use, so please refrain from purchasing if you are concerned. I have confirmed that it sends MIDI signals when connected to a PC via USB cable. Regarding the software download card included with the main unit, I have not used it. I cannot guarantee what apps are currently available or whether you can actually download them. Therefore, please refrain from purchasing if you intend to use the bundled software. Accessories: Box, USB cable, batteries Please note that we cannot accept price reductions. Please check the manufacturer's website for operating environment information before purchasing. --- Keyboard: Natural Touch Mini Keyboard Number of Keys: 25 Controllers: Joystick, Arpeggiator Button, Sustain/Tap Button, Octave Shift Button Octave Shift: -4~+4 Wireless Method: Bluetooth Low Energy (Apple Bluetooth Low Energy MIDI standard compliant) USB Port: B port Power Supply: Two AA batteries (for wireless connection, alkaline or nickel-metal hydride batteries), USB bus power (for USB connection) Battery Life: Approximately 30 hours (when using alkaline batteries) Current consumption: 100mA or less Dimensions: (W) × (D) × (H) 395 × 131 × 52 mm (microKEY Air-25) Weight: 670g (without batteries) (microKEY Air-25)