Kensington Orbit Trackball
This came out in 2004.
This one is Star Trek looking. No scroll wheel. 2 buttons only.
2 Buttons. Require the software TrackballWorks to customize buttons.
though, someone used this trackball to play the game osu well!
for osu game, see Which is More Efficient for Pointer Control? Comparing Mouse, Trackpad, Touchpad, Joystick, Pen Input.
Ball diameter: 40 mm