Kensington Slimblade Trackball [72327]

Product description ※Please note that product information is not in full comprehensive meaning because of the machine translation.

A 4-button USB trackball with a laser sensor.
In addition to moving the cursor as a normal trackball, you can scroll up and down by twisting the ball to the side.
You can also switch the operation mode and assign the desired function to each button with the utility software distributed at the manufacturer's site.