The one in the back is a mock-up made out of an old tractor muffler, some scrap tubing & pipe and other odds & ends. I live way off the beaten path and there are always people driving all the way up my road past numerous Keep Out, No Trespassing, and Private Property signs, "just to see where it goes". I placed the "gun" right where they turn around when they see there's a house here. When I actually see somebody doing it, I grab an old ammo can and make a run for the gun...
Usually they can make the mile and a half back to the pavement in just a few seconds.
I finally gave up on just safes awhile back and built a reinforced underground block & concrete vault with a motion sensor inside wired to an old fire engine siren, well hidden and pointed at a couple neighbor's houses a mile or so down the hill. If they manage to find the vault in the first place, they still have to blow a hole in it or jackhammer it, then they still have to get into the safes after that. Oh, and get by me too, I'm here most all the time.
How many are in there is a mystery...
Lets just say that pic was taken awhile back.