Ergonomic trackball mouse: with the smooth, precision trackball, you no longer need to move your arm for cursor movement. Your thumb will control the cursor instead. It will effectively reduce fatigue and tension for your wrist and arm -Bluetooth & 2.4g wireless connection: this ergonomic mouse has dual bt 4.0 and 2.4g wireless connection modes (nano usb receiver stored at the bottom of the mouse), you can connect up to 3 different devices at the same time, switch freely between android , tablet and mac with just one button -Rechargeable with USB-C port: the built-in bluetooth trackball mouse 500mah lithium battery. There is no need to change the batteries. It can last 1 month for a complete refill. Please remember to turn it off if you don’t use it for a long time -3 adjustable dpi: 3 adjustable dpi level 800/1000/1600, easily change the sensitivity of the cursor depending on your activity. Provide a fantastic user experience of quick response, smooth tracking, precise movement -Wide compatibility: works universally with windows, android, m .c os desktop laptop, etc. bluetooth mode works with windows / android /mac os system, will not occupy any usb port. 2.4ghz mode works with laptop, desktop or any device with usb port, just plug the usb receiver into the usb port and you are ready to go ✔️Product Features:1. smooth and precision trackball ( With the trackball, you don’t need to move your hands when you work or play, so there is no fatigue with your hands)2. 2.4g wireless usb and bluetooth dual-mode3. ergonomic design4. high sensitivity with 3 dpi levels5. rechargeable with usb port c6. connecting up to 3 devices simultaneously ✔️Specifications:Working distance: 10mDPI level: 800/1000/1600Click life: more than 3 million timesLithium battery capacity: 500maSize: 115 * 92 * 71mmWeight: 171gTrackball Size: about 3.2cm in diameter