ERGONOMIC TRACKBALL MOUSE: With the smooth and precision trackball, you no longer need to move your arm for the movement of the cursor. Your thumb will control the cursor instead. It will effectively reduce fatigue and strain for your wrist and arm BLUETOOTH & 2.4G WIRELESS CONNECTION: This ergonomic mouse has dual connection modes BT 4.0 and 2.4G wireless (USB Nano Receiver stored in the mouse bottom), 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 Bluetooth Trackball Mouse built-in 600m Ah lithium battery. No need to change batteries. It can last 1 month per one full recharge. Please remember to turn it off if you do not use it for a long time