ECHTPower(TM) 2.4G Wireless Mouse 1200 DPI - 3 Button Optical Slim Ergonomic Design with Nano Receiver (Red+Black) High speed wireless transmission- 2.4GHz Wireless working distance is 10m so that it provides a reliable connection, which is handy to move and gives you a fresh moving speed It contains a built-in Nano receiver, which is easy to take out and plug in. It can also help users solve the trouble of losing receiver Up to 9-month battery life- The long battery life virtually eliminates the hassle of changing batteries (Battery life may vary based on user and computing conditions) Long time service life- 5 million times long time button with durability, adopt Omron fretting, excellent click feeling Stand-by mode automatically- Four automatic sleep mode design, can effectively extend the using time, with the power switch, you need to turn off the power switch when not in use