bout this item 2.4 GHz Wireless Connection, Ergonomic Design, Energy and Electricity Saving, Plug and Play, Intelligent Dormancy, Drop Key Cap, HD Laser Engraving Fonts, Comfortable Experience Special Hand Feel Stylish Ultra-Slim design Keyboard & Mouse, Sealed membrane for overall protection, Brush metal finish, Advanced controls. Battery Type : AAA Professional Optical sensor with direct DPI switch 800/1200/1600 dpi, High quality switches for over 2 million clicks supported Smooth responsive cursor control with easy scrolling, Designed for professional or gaming use