ERGONOMIC TRACKBALL MOUSE - The comfortable ergonomic mice will naturally fits your hand, lower muscle strain, more natural posture. A cordless trackball mouse with easy thumb control, precision and smooth tracking2.4G & BLUETOOTH CONNECTION - Use your track ball mouse with up to 3 devices: one via 2 4GHz nano dongle that stows inside the mouse buttom and two via Bluetooth 4.0. Switch freely between your Windows or Mac computers with just one button3 ADJUSTABLE DPI LEVELS - You can adjust the thumb mouse among 3 resolutions of 1000 / 1600 / 2400 DPI depending on your needs. Just press the DPI button to change the cursor sensitivity fo your ergo mouseRECHARGEABLE BLUETOOTH MOUSE- With built-in 600mAh rechargeable lithium battery, the bluetooth trackball mouse has a long battery life which will stays powered for 1 months on a full charge (Type-C charging cable included)EASY MAINTENANCE - The trackball is very smooth, and its large size can prevent dust and dirt from clogging them. The ball is held in place by the ball bearings, but can be easily popped out of the device, by pushing it through the hole in the bottom. You can clean it after a period of usage with soft cloth