If you're not sure whether or not your vehicle has a G80 locker, there are a few things you can check for. First, look for an external plug on the differential cover. This is where the locker's air line connects. Next, check for a sticker on the differential cover that says G80 or gov-lock. If you see either of these, chances are good that your vehicle has a G80 locker.
To be absolutely sure, though, you'll need to consult your owner's manual or contact the manufacturer directly. Once you know for certain that your vehicle has a G80 locker, you can start enjoying all the benefits it has to offer!