ADESSO 2.4ghz RF Wireless Mini Keyboard With Optical Trackball USB Receiver Adesso 2.4ghz Rf Wireless Mini Keyboard With Optical Trackball (Usb Receiver). Input Device Type Keyboard; Device Form Factor External. Connectivity Technology Wireless; Interface Type USB. Input Device / Keys Qty 87 keys; Keyboard Technology RF. Manipulator Trackball; Battery Type AA Type; System Requirements / OS Required Windows 7/ Vista/ XP/ 2000.