This product is a portable finger handheld 4D USB- powered trackball mouse. It adopts a desktop design and can be operated freely and comfortably without limiting the operating space. It is an choice for laptop users. Just use your thumb to control the 4D page scrolling function. It supports plug and play, software is required. Therefore, it is indeed an excellent 4D USB trackball mouse to choose from. Features - Color: mainly black. - Material: durable hard. How to Use 1. Insert the finger or into the hole of the mouse 2. Control the trackball to move the , and then press the left and right buttons with your thumb 3. When using the " " function, please press a button with the same function as the left button of a normal mouse in 4. Use the left button to lock the screen, and then you can control the trackball to scroll the screen freely Package list: 3 x Mini Trackball Mouse