G-Drive compatibility with older OSXs

I have a MacBook Pro, running system 10.8.5. I want to buy a mobile USB G-Drive for backing up, but the specification for these drives says that they all require system 10.9 or later. Is this really the case? If I buy one of these drives, will it be incompatible with my system? If this is the case, then doesn’t G-Technology sell some form of drive that is compatible with system 10.8? It seems crazy that I’m trying to update my system to Sierra, and can’t do this because I can’t find a compatible drive to back-up onto first.
Any help appreciated.

It will technically work with a 10.8 system without issue.

Okay, so I bought the G-Tech drive, and already have problems, on day one. The G-Tech will back-up the contents of my Mac’s Home Folder, but that’s all. It cannot see the whole hard drive, and so cannot back it up. How do I get around this, please?

What method are you using for backup? No hard drive can be stopped from being able to access the entire drive without something else blocking it. The device is just an empty drive that can store data. Even Time Machine will backup the entire computer by default.

I’ve since resolved this issue, after three hours on the telephone with Apple.

I had never used Time Machine before. But mine defaulted to backing up only the Home folder, not the entire Hard Drive. The only way around this was by using some code that Apple passed on.

The problem I encountered is the G-Technology Assistant application requires OS X 10.9 or later, but I’m on an old iMac at 10.6.8 which I believe can’t be upgraded.

It seems too bad that the app can’t be made to run under older OS X.