I have been using trackballs ever since I got my first computer. This one ranks dead last. You would think the new technology would be great, but it's a drawback. I could only stand to use this trackball for 3 hours due to the fact that my onscreen mouse movement was very jerky. I need precise and smooth movement to do my job and can get it with a Logitech. I sold this mouse on eBay for a profit.