Adesso Tru-Form WKB-3150UB Keyboard - Compact - Wireless Connectivity - USB 2.0 Interface - Trackball - English (US) - Black - Membrane Keyswitch - RF - 9.14 m - 2.40 GHz - 87 Key(s) - 20 Hot Key(s) - On/Off Switch, Connect, Play/Pause, Stop, Previous Track Hot Key(s) - Windows Vista, Windows XP, Windows 10, Windows 8, Windows 7, Windows 2000 - Notebook/Tablet - PC - AAA Battery Size Supported