Based on customer feedback of last several months, we made some improvements to make the mouse better:Solution about Connection. There were 5% customers met them. Because No Bluetooth Chip can match more than 1000 Bluetooth drives, after lots of tests we chose the best Bluetooth 3.0 Chip – AIROHA AB1129F. The issues can be reduced from 5% to â‰¤1%. If any issue, automatically reinstall a new Bluetooth drive can solve it at most times.Solution about Battery. We adjusted the structure to keep the battery system stable, to prevent it damaged during transport. And we upgraded the battery capacity from 600 to 750 mAh, it can run 2 weeks with 8 hours every day. Solution about Sleep & Wakeup. We spent much time on the balance between power save and fast wakeup. The mouse will fall asleep after 10 minutes no-operation, when you use it, click any button and waiting 1-3 seconds, it will wake up. If you won’t use it for a long time, we suggest you to turn the switch to off for saving battery.Besides, we also modified the mice edge for more comfortable feeling, changed the scroll wheel for complete noiseless… We always do our best to improve customer experience. Thanks for choosing UHURU and welcome your reviews.Specifications: Bluetooth Version: Bluetooth 3.03 DPI Levels: 800/1200/1600750Mah rechargeable battery capacityOperating Range: Max.32.8FTDimension: 4.3″x2.3″x0.8″(LxWxH)*Weight:55gNote!!The mice fit â‰¥99% devices, but connection issues may happen in very few cases. Delete current Bluetooth driver and automatic download the proper Bluetooth driver can solve it most times, or we will refund all you paid.If your device doesn’t have Bluetooth function, you need to install a Bluetooth dongle first.Turn off the on/off switch if you won’t use it for long time.BEST COMPATIBLE BLUETOOTH 3.0 CHIP. Compatible with more than 98% Bluetooth devices. Effortlessly connect in 3s to PC, laptop, notebook, Mac; Support Win7 Win8 Win10 Linux OS X or Android tablet. Intelligent connectivity & no code required. Bluetooth V3.0 is backward compatible with all Bluetooth versions.