Neu Finger HandHeld 4D USB Mini Portable Trackball Mouse PC Laptop Computer Function: new and high quality Quantity: 1pc Color: Black br or > Small size, light weight, easy to carry Suitable for left and right handed users Compatible with all operating systems Windows and, Unix, system etc. nResolution: 800DPI The length of 2 meters Product size: 7.5cm x 6cm x 4.5cm How to use: Place your finger or middle finger in the mouse hole. Control the ball to move the cursor, then press the right button to use the thumb. When using drag and drop functions and CRP, press the button in the hole in the same function as the mouse, left mouse button together Use the left button to lock the screen, and then you can control your trackball screen scrolling Package includes: n 1 x trackball mouse (with retail package)