Kensington trackball button
I know that this posting is a "shopping" type question and falls outside the normal design type questions accepted here. But I know the frustration that can occur when a favorite mouse starts to get really flakey and the buttons lose their click!!

This particular type of switch is commonly used in various types of computer mice and track ball units. I have replaced many of the same type in mice that have become old favorites but used so much that the switches simply wore out. Here is the replacement unit in the Mouser catalog.

 



I purchased my replacement switches in quantity at the time of ordering a few years ago and have used them to repair at least three models of computer mouse.