EX-G Left-Handed Trackball Mouse 2.4GHz Wireless Thumb Control Left Handednn--u300AOptical Tracking Technologyu300BThe EX-G series trackball provides precise cursor movement for superior accuracy so you can get where you want on the screen quickly with less hand movement, improving productivity and efficiency. This mouse is designed for a LEFT-HANDED person.nn--u300AFunctional 6 Buttonsu300BIt is very easy to move in any direction. It comes with 6 physical buttons on the device and the two extra buttons are the scrollwheel tilting that allow horizontal scroll. Mouse Assistant software can be easy to customize button functions, it is available to download from US website.nn--u300ADPI CURSORu300BDesigned with a high-performance gaming optics system sensor and lens. The DPI button can easily change between 750LOW and 1500HIGH DPI, making the movements of your cursor faster or slower. Comes with a BLACK BALL that can be replaced with a RED BALL sold separately.nn-.