Keys:25 velocity-sensitive keys; Knobs:1 assignable endless 360 degree encoders; Output: 3.5 Sustain pedal connection port;USB-C port;Wireless connection with for Windows/for Mac/for iOS/for Android Wireless Midi Out Function(Need extra wireless midi device) Power:780mAh Battery supplied or USB-bus-powered(only include the USB cable) How to connect:USB Connection : Plug the cable through the USB-C port to the for Windows/for Mac it will automatic be recognized , When plug into Windows/Macthe SMK-25 MINI will be charging at the same time;(Red light: charging , Green light:charging complete) Wireless Connection: Press and hold the BT button, when the light flashingthe wireless function is activated , when the light stays on was connection successfully; Wireless Adapter: Plug Wireless Adapter B into for Windows/for Mac, connectionwas successfully when both lights stay on; Direct Wireless : Activated Bluetooth function of for Windows/ for Mac/ for iOS/ for Android Select SMK-25 on the list (for Windows users need Bluetooth 5.0 and extra BLEMidi Driver) ;Note: for iOS/for Android need software support BLE MIDl, and connect inside thesoftware ; MIDI OUT Connection:Cable Connection : Change the Pedal mode setting in software form Pedal to MIDI OUT , When it's done , the 3.5mm Port in the side of the keyboard canuse as a MIDI OUT port to connecting to device such as hardware synthesizerWireless connection : Use Five-Pin wireless MlDl adapter A connecting todevice such as synthesizer or other device that support MIDIIN;(you need to buy the M-vave )midi adapter Color: White Material: ABS Package Contents: 1 x SMK-25 Mini MIDI Keyboard