Fingertip-based controls allow for quick and accurate movements. Use the left button at the top of 4D Trackball Mouse to lock the web page. Then control the trackball to scroll the screen freely. The left click key is inside the hole of the 4D Trackball Mouse . Hold 4D Trackball Mouse in your hand like a trigger and use your thumb to move around. Sculpted shape supports your hand staying in one place, move the cursor without moving your arm. Suitable for both left and right-handed users.