Cobra,
They are three inch. Mine is buried in the safe but I will check next time I'm in there (probably today) to see what dash it is. Probably -5 since is is MIM w/o a lock.
There are many versions of the backpacker, but I've only seen two of these "Mountain Backpacker" versions, mine and the other posters.
I actually go to Alaska on occasion and spend my time in the deep woods. I usually carry my .44 magnum mountain gun, but this one may make the next trip. Fortunately, the only thing I've shot with the mountain gun is spruce hens (ptarmigan) for supper! I need to find a good 18 or four inch 17 to carry along as well for spruce hens.
I told my buddy that the next time we went, I was just taking a .22 pistol, cause all I shoot is spruce hens. He asked "What about the bears?"
I replied, "If we see a big bear, I'm going to shoot you in the knee, and I don't want to hurt you too bad, I just wanna be able to outrun you!" :>)