Ergonomic contour design - Minimizes pain and discomfort in forearm muscles from twisting which can cause carpal tunnel syndromeBuilt-in 2??? large trackball with optical sensor - accurately and precisely tracks with less muscle movement for maximum comfortEast to install programmable driver - friendly user interface that lets you change button assignments DPI sensitivity scrolling speedRemovable trackball - Can Be easily removed by pushing the trackball from underneath the mouseAdjustable DPI switch - adjustable cursor moving speed from 400-4 800 DPINote : In case of Wireless mouse, the USB receiver will be provided inside or along with the mouseMeet one of the newest models of the Adesso Trackball product line the Adesso iMouse T50 This device is cable-free by utilizing the 2 4 GHz radio frequency technology offering a wireless range of up to 30 feet It???s also fully programmable meaning every mouse button can be customized to your preferred function with its programmable driver With its 5 levels of DPI resolutions (400-4800) the optical trackball provides superior accuracy and smooth motion reducing hand movement and space This mouse trackball is also easy to maintain ??? just push trackball outward from back clean and push it back in place Its ergonomically contoured 2??? large size trackball and adjustable leg stands further completes its ergonomic advantages making your daily computing tasks more comfortable and stress-free