E-Blue Vertical On-Air 2.4GHz Wireless Mouse (EMS148GY) Ultra quiet clicking buttons provide distraction-free navigation 2.4G Wireless transmission distribute stable signal within 30 ft. radius Adjustable 3 tracking speeds switch (500 / 1000 / 1800 DPI) Red Wave Sensor operates on most surfaces including glass Dazzling LED illumination with ON/OFF switch Intelligent power-saving sleep-mode saves batteries life Intelligent power-saving sleep-mode saves batteries life Intelligent power-saving sleep-mode saves batteries life No Drivers Required, 'Plug and play'