This might not be the right place to ask. I bought a used one a few years ago from a gun store. I really didn't pay attention to the exact model when I bought it. I figured it was a 92 f. I was talking to someone recently and said yeah I have a Beretta 92 but don't remember if it's an f or fs. Since I never really looked i went home to see and much to my surprise it's a g. So I did some searching and see there's sub models. My question is how can you tell which one it is?