It can be operated in ways suitable for long-term use without causing strain to the wrist or muscles No limitation of operational space Helps avoid sitting too close to the monitor, reducing eye fatigue Plug and play, no software required Designed for both left and right-handed users Ideal for laptop users Compatible with Windows 95, 98, 2000, ME, XP, NT Unit Dimensions: 3.15 x 2.05 x 1.97 inches (8 x 5.2 x 5 cm) USB Cord Length: 73 inches (186 cm) Color: Black How to Use: Place your index or middle finger into the hole of the mouse Control the trackball to move the cursor and press the right and left buttons with your thumb For the "Drag and Go" function, press the button inside the finger hole, which operates like the left button of a standard mouse Use the left button to lock the screen and control the trackball for smooth scrolling Material: PVC and silicone Package Includes: 1 x Hand Held 4D USB Mini Trackball Mouse Note: Lighting and display differences may cause slight variations in color between the image and the actual item Measurement may vary by +/- 1-3 cm