abcGoodefg 2.4G Wireless USB Handheld Finger Trackball Mouse (Black+Red) Plug and Play, easy to install. Wireless, With trackball, cool. Press then apper laser pointer for presentation Special design, can avoid the harm on your wrist and muscle, greatly reduces discomfort for Arthritis and CTS suffers. Easy to use - left or right hand, or cradled between both Hold in hand or place on any surface Ideal for both laptops and desktops. Place end of index or middle finger on trigger button & thumb on roller ball Compatible with :Windows98/ 2000 / XP / VISTA / win 7/Linux/ Unix/ Mac OS