E-BLUE Estilogic RF 2.4 Wireless Keyboard + Mouse is the world's first keyboard with built-in micro receiver, the inventive 2.4 GHz duo-frequency makes it feasible to use wireless mouse without carrying energy-saving IC Battery life lasts for 3-6 months. With 2.4GHz wireless technology, usage extent achieves up to 10m making applications more efficient and devoid of interruption or supsension , resulting a more superior performance than conventional wireless keyboard + Mouse.