Trackball Explorer combines a finger-operated trackball with IntelliEye optical technology for superior precision and accuracy. The ball is large and conveniently located for easy control. Trackball Explorer has an ergonomic design that supports your entire hand and fingers. With no rollers or gears to clean Trackball Explorer will stay precise, as if it were "brand new." Trackball features smooth feel and programmable forward and back buttons for easier Internet navigation. The IntelliEye sensor scans 1, 500 times per second, resulting in smooth, controlled movement. The wheel makes scrolling simple without using scroll bars and helps you work 25% more efficiently.