I installed the progressive EMSHW30C Surge Protector in my camper, with the remote display.
It has several, worthwhile, features and it is nice to be able to see electrical conditions, like incoming voltage, current usage and last previous error, if any, from the remote display.
The incoming line frequency status is of less interest, pretty sure that has to be a constant or the grid would not be happy.
It has saved things a couple of times and I feel it has paid for itself.
Man you folks north of the border are getting hammered by the exchange rate