AS-IS Kensington TurboBall 64227 Trackball Mouse 4 Buttons USB Ergonomic
Item is as-is, doesn't work as smooth when rolling up or down, but sideways seems betterIt seems the rubber roller for the vertical slips / does not make good contact with ball or has softened due to age and slips or does not roll as smooth that direction for some reason. If you push down sometimes it will work better but not as smooth.
Rubber roller pin may need replacing or maybe you can take the rubber off the pin (rubber over a steel pin) and find some rubber wire sheathing of same size. or coat with some liquid rubber?, or maybe something can be adjusted? We do not have time to experiment, so selling as is.
all sales final, sold as you see it