This is the Zodiac 1.1 OS flash update.

** USE AT YOUR OWN RISK! **

This file flash updates the OS ROM in early production Zodiacs and if not done properly your Zodiac could end up a very expensive paperweight. Not sure if you need it? Open the menu from the launcher screen and select Info, then tap on Version and look at what Palm OS version you have. If it's 5.2.7 then you already have the update and don't need this file.