Macintosh II and SE to Beige G3
This is the first ADB (Apple Desktop Bus) mouse made for the Mac. Model number G5431 was introduced with the Macintosh II and SE. It will work on all Macs through the beige G3 and the Apple IIGS. The Apple IIGS mouse is identical except for the model number.
The last picture shows the two variations of this model number. The top and case look identical, the original is the one on the left with the black (or dark gray) mouse ball. The one on the right with the gray mouse ball is a later model. The gray ball is larger and they are not interchangeable.