... 4Ghz WirelessWireless Operating Distance :10mBattery Size Support :2 x AAA battery (not included)4 keys (left, right, scroll, resolution ... meters.Built-in mouse memory, no recoding is needed after battery replacement.Intelligent connectivity, no need to code, plug and play ... Cautions: Operation distance is closely related to the environment.Battery life may be different for personal habit of using ...