??????Optical Tracking Technology???The ELECOM "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. ??????Functional 6 Buttons???It 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. ELECOM Mouse Assistant software can be easy to customize button functions, it is available to download from ELECOM US website. ??????DPI Cursor???Designed with a high-performance gaming optics system sensor and lens. The DPI button can easily change between 750(LOW) and 1500(HIGH) 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). ??????Easy Maintenance ???The ball rolls on three 2.5 mm large artificial ruby ball bearings. They are extremely smooth and the relatively large size prevents dust and dirt from clogging them. So you don???t have to clean the ball bearings too often. The ball is held in place by the ball bearings, but can easily be popped out of the device, by pushing it through the hole in the bottom and it can be easily cleaned. ??????Product Details???System requirements: Windows 8.1, Windows RT8.1, Windows 10, Windows 11 (Horizontal scrolling function is not working in Windows RT8.1), macOS 10.10, Size: W3.7"(94.7mm) X L4.9"(124.4mm) X H1.9"(47.7mm), Weight: 5.3oz(without battery), DPI: 750/1500 count (switchable), Connectivity: 2.4GHz wireless