We haven’t configured it so I have no idea if or how it works. What I do know, is that you don’t get any rails to put it into a 19 inch rack. Since Google does not sell separate rails, you’re left with sticking it in the rack by its ears (example here). Since the box is small and light (hence the term “mini”) you could pull this off, but I found this rather unprofessional and crappy. I wanted to have rails, also because all the other servers have them too 😉
I went to my local hardware shop (Magna Computers) and tried several sets of rails. None of them would fit without modification, but eventually I found one that needed only 1 extra hole in each rail. These rails ship with 19 inch Chenbro server cases, and have product-id 84-210710-024.
The rails are 26 inch deep, and fit very nicely into our Dell rack.