ERGONOMIC DESIGN for MORE COMFORT: Unique adjustable hinge allows you to customize the trackball angle from 0 to 20 degrees according to your needs, ensuring a more natural, comfortable hand position for all-day comfort Precise Thumb Mouse: ProtoArc trackball mouse provides accurate and smooth tracking, allowing for easy navigation through documents and web pages. You no longer need to move your arm for the movement of the cursor. Your thumb will control the cursor instead via the trackball. It will effectively reduce fatigue and strain on your wrist and arm. More productive in the narrow space, such as the messy desktop, couch, bed etc. Note: this trackball mouse is not an ordinary traditional mouse. Bluetooth & 2.4 G Wireless Connection: PLUG and PLAY. This trackball mouse has triple connection modes. You can control three devices at the same time, switch freely between PC, laptop and iPad with just one button to improve your efficiency. Compatible with Windows, Android, Mac OS