Built-in Rechargeable Li-Battery with Auto-sleep Function:The iFun Wireless Mouse has 650mA battery capacity,only about 3 hours full charging time needed and support 720 hours working.Enters power saving mode automatically after 8 minutes idle,press any button can wake it up,conserves power and extends product life.If the mice lack of power,connect the charging cable,then it can work simultaneouslyScientific Ergonomic Design with Next/Previous Buttons: Contoured shape, sweat-resistant ,skin-friendly finish,added next/previous buttons to browse web page faster,sturdy scroll wheel with rubber oil coating that prevents fingers from sliding,the ergonomic computer mouse allow for natural hand positioning and ultimate comfort. It eases tension on the wrist and hand for right-handed users.Encourages healthy natural "handshake" wrist and arm positions for smoother movement and less overall strain4 Adjustable DPI Levels:800,1200,1600,2400, easily change the cursor sensitivity depending on your activity. Resolution Optical Tracking Technology provides more sensitivity than standard optical mice for smooth and precise tracking on a wide range of surfaces.Best for things that require precision like color correcting and photo edits or make it faster for browsingPlug-and-play and Wide Compatibility:Comes with a USB Nano receiver, plug and play directly.2.4GHz wireless technology ensure longer working distance-up to 33ft in 360 degree with no interference.Well compatible with Mac OS X, Linux and all versions of Windows such as Windows7/8/10/XP etc. Fits for desktop, laptop, PC, Macbook and other devices.