Description The item is a portable finger hand-held 4D USB powered mini trackball mouse, which is designed with off-table design for free and comfortable operation without limitation of operational space, and for laptop users. 4D page scrolling function can be controlled simply by your thumb. It supports plug and play, no software required. Therefore, it is really a wonderful 4D USB mini trackball mouse for choice. Features - Color: mainly black. - Material: durable hard plastic. - and Portable Finger Handheld 4D USB Powered Mini Trackball Mouse. - Off-table design and without limitation of operational space, for free and comfortable operation. - for laptop and desktop users. - 4D page scrolling function can be controlled simply by your thumb. - Features 3-button design with thumb-controlled trackball. - USB 2.0 interface, plug and play, no software required - Easy to use: fit for left or right hand, or cradled between both. - Mini size, light weight and easy to carry. - Compatible with Windows 95/ 98/ 2000/ ME/ XP/ NT. How to Use 1. Put your index or middle finger into the hole of this mouse. 2. Control the track ball for moving cursor and press the right and left button with your thumb. 3. When using "Drag and Go" function, press the button in the hole of the mouse that has the same function as the left button of the common mouse. 4. Use the left button to lock the screen and then you can control the track ball to roll your screen freely.Package list: 1 * Portable Finger Handheld 4D USB Powered Mini Trackball Mouse (Black) Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.