What does a pressure regulator look like?
If you have a faucet with a hose bibb on it, a faucet like those used in a laundry tub, you could go to a big box store or hardware store and purchase a threaded on pressure gauge to check the existing water pressure. I have one and use it a couple times a year to check my in-coming pressure. This will let you know just what the pressure is.
Yes, that looks like a simple water regulating valve that adjusts the in-coming water pressure. Adjustments of the pressure higher or lower are with a screw driver.