Electric Water Heater

I recently inspected an electric water heater in Calif. that had just been replaced. The breaker on the electrical panel was off when I arrived so I turned it on. Other than that, does an electric water heater have an on/off switch? Also, I did not see a thermostat on the exterior of the appliance. I don’t usually take appliances apart to inspect them. Question: would there have been thermostat under the cover plate?

yes, high and low plates