Ergonomic Vertical DesignEncourage healthy natural handshake wrist and palm position for the most comfortable grip, less wrist strain. The ergonomically- designed thumb rests and grips fit the contour of your palm for maximum comfort, perfect for Small to Medium Sized Hands.The surface of the mouse is sprayed with rubber oil, which is very comfortable to touch.This mouse is very suitable for people with RSI or customers who use the mouse for a long time. Easy to useJust plug the included USB receiver into the USB port of your computer, no other additional software needed(the receiver is at the bottom of the mouse).Not Bluetooth.New to Vertical Mouse will adapt to for a while, after using you will love it. Automatic sleep function The sleeping function is for saving energy, it goes to sleep when you are not using it for 10 minutes, and you only need to click any button on the mouse once, it should be back to work. When the receiver is recognized by the computer, it&#