Neu Finger HandHeld 4D USB Mini Portable Trackball Mouse PC Laptop Computer Feature: new and high quality Quantity:1pcs Color: Black Usb-2.0-schnittstelle, plug and play, no need to install any software 4D page scrolling function can be controlled by a thumb Special designs that can damage and avoid muscle in the wrist Small in size, light in weight, easy to carry Suitable for left-handed and right-handed users Compatible with all of the operating system windows and, Unix, systems, etc. Resolution: 800DPI The length of 2 meters Product size: 7.5cm * 6cm * 4.5cm; How to use: Put your finger or middle finger in the hole in the mouse. Control the ball to move your cursor, then press the right button to use your thumb. In the use of drag and drop functions and CRP, press the button in the hole in the same function of the mouse, the left mouse button together Use the left button to make the screen lock, and then you can control your track ball screen roll Package includes: 1 x track ball mouse(with retail package)