The kids returned from a Children's day festival with a bag of more or less worthless trinkets, among them a lovely KitKat promotional ball mouse. Its fatal handicap is the connector - the last time I had a PS/2 in my machine was a decade ago ...
Fortunately there was an old USB laser optical mouse lying in my drawer.
The scroll-wheel is broken, but since KitKat doesn't have one it's not a problem :-)
The PCB was too large to fit into the enclosure and the switches needed to be repositioned.