Trackball Comfort: A 34mm thumbcontrolled trackball lets you move the cursor with your thumb, reducing wrist motion and fatigue. Works on desks, couches, legs, and other surfaces without a traditional mousepad.<br> Ergonomic Vertical Design: Keeps your hand in a natural wrist and forearm position for smoother movement and less muscle tension. Palmfriendly and comfortable for extended use. Plugandplay with no driver required.<br> Noiseless Buttons: Silent left and rightclick buttons suitable for latenight work and quiet environments such as libraries, hospitals, or meetings.<br> 4 DPI Settings and Web Navigation: Switch between 400/800/1200/1600 DPI for precise control across tasks from graphic design to browsing. Builtin Back and Forward buttons speed up web navigation.<br> Use Scenarios: Ideal for long desk sessions with documents or spreadsheets; catching up on emails while lounging on a sofa; light photo editing or graphic work where precise cursor control matters.