Merlin MannWhatever this is, it looks like the kind of thing my late grandmother would get talked into buying.
Laxdude@hotdogsladies sorry to be Mr Serious Answer, it looks like a temporary(?) dry sprinkle switch head. So the part that keeps the water out of sprinkler pipes until a head pops and the most god awful rusty water flows. But it doesn’t appear to be wired or active (valves are closed). Why yes, I do work at a museum. How did you know?
@Laxdude Seriously thank you!
@hotdogsladies It's not wired up, has no air compressor and it better get a shed over it to secure it and stop it from freezing if it's permanent. Dry means it's for a museum like space (because 'air' is smaller than water it can't drip) or a parking lot that might freeze (which seems unlikely for your area)
And you are welcome.
@Laxdude A San Francisco residence. I think it's either a duplex or maybe a four-plex.
It's been undergoing a seismic retrofit for literally years.
Maybe it's money laundering? I honestly have no idea.
@hotdogsladies Probably a modern code thing then. Dry means less maintenance and risk of water damage. You might also have seismic sensors to prevent water flowing unless there is also fire? There are a LOT more wires than we have up here in Western Canada on the valves.
: j@fabrica:~/src; 
@Laxdude @hotdogsladies I was wondering, the backflow prevention looked all wrong for an irrigation setup. But I makes more sense to realize that it’s trying to take water in from outside, and keep the bad water in the pipes. Totally the opposite of keeping pesticides out of the building water lines!
@josephholsten @hotdogsladies it's air pressure keeping a valve closed against the water pressure. Probably behind the lower canister is a water inlet (or it hasn't been plumbed) maybe at straight main pressure.
Knowing a bit about a system meant I saved work about a million in water damage but had to ask "are you sure we aren't on fire, I'm going to shut the water off"