It can be operated for long-term use without causing strain to the wrist or muscles. No limitation on operational space. Helps maintain a comfortable viewing distance from the monitor, supporting better posture and reduced eye fatigue. Plug and play—no software installation required. Designed for both left-handed and right-handed users. Ideal for laptop users. Specifications: Compatible with Windows 95, 98, 2000, ME, XP, and NT. Unit Dimensions: 3.15 x 2.05 x 1.97 inches (8 x 5.2 x 5 cm). USB Cable 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; use your thumb to press the left and right buttons. The button inside the finger hole functions as the left-click button. Press the left button to lock the screen, then use the trackball to scroll freely. Material: PVC and silicone. Package Includes: 1 x Handheld 4D USB Mini Trackball Mouse. Note: Colors may vary slightly due to monitor settings and lighting conditions. Measurements are subject to a tolerance of ±1–3 cm.