ERGONOMIC DESIGN - EIGIIS handheld trackball mouse wireless can greatly avoide the harm of palm and muscle of your wrist for long time using mouse. ATTENTION: NO LASER POINTER. IF YOUR MOUSE IS NOT WORKING WHEN YOU WENT A FEW MINUTES WITHOUT USING IT, PLS KINDLY CLICK TO WAKE IT UP.IF STILL NOT WORKING, PLS CHECK BELOW ISSUES: 1, CHANGE BATTERY AND TRY; OR 2, TURN IT OFF AND ON; OR 3, REMOVE THE USB RECEIVER AND TRY IT. IF STILL NOT WORKING, PLS DON'T HESITATE TO CONTACT US FOR A REPLACEMENT TRACKBALL COMFORT - Ergonomic handheld trackball mouse wireless is a best choose to reduce the chances for Arthritis and CTS suffers. Hold EIGIIS ergonomic handheld trackball mouse wireless 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 hand - style, no space limitation, left/right clickers, fit left and right handed users. ADJUSTABLE DPI - EIGIIS ergonomic wireless handheld finger trackball mouse have 800/1200/1400/1600 DPI resolution optical tracking technology that provides higher sensitivity than standard optical mice.EIGIIS handheld trackball mouse wireless have a Sensitive rolling ball and frequency stable 2.4GHz receiver(For wireless mouse, the valid range distance is about 10M, the signal cant go through wall). Powered by One AAA battery (not included) WIDE APPLICATION - EIGIIS handheld trackball mouse wireless including USB 2.0 interface, plug and play, no software required. Suitable for laptops and desktops, but NOT FOR TABLETS AND CELLPHONES. Compatible with: Windows XP / VISTA / Win7/ Win10/ Linux / Unix / Mac OS. WHY CHOOSE TO BUY EIGIIS TRACKBALL MOUSE - product quality assurance. If you are dissatisfied with the product you received or have quality problems, please feel free to contact us. We will give you a full refund or send a product to you again. Click the "Add to Cart Button" at the Right of this Page to Order Your Set Now! Enjoy the EXCELLENT SHOPPING EXPERIENCE. ANY PROBLEM, PLS CONTACT US FOR REFUND OR REPLACEMENT.