Macintosh Mouse (original, beige, 1984)

This original Macintosh Mouse, Model M0100, shipped with a Macintosh 512K. This mouse was compatible with the Apple Lisa and was the same mouse that shipped with the original Macintosh. 

The original Macintosh Mouse used a DE-9 connector and remained unchanged until 1987 when its color was altered to Platinium (with Smoke accents) to match the Macintosh Plus. Like all early Macintosh mouse designs, it used only one button to control the famously easy-to-use Macintosh operating systems of the time.

Source: Wikipedia