The MSA minimizes the amount and duration of the surge that comes in via the utility's electric system to a safe voltage that most appliances can tolerate. Most sensitive electronic equipment (i.e. televisions, stereos, computers, faxes, printers, etc.) may not tolerate that voltage and will require a second line of defense provided by a “point-of-use surge arrestor”. The surge protector passes the surge along from the device to the system ground. YVEA does not verify the integrity of your home’s grounding system.