A:Answer As mentioned in another response to this question, a gfci "monitors" current on the line, neutral, and ground conductors to determine what to do. So it can protect downstream devices if they are connected to the "load" side of the gfci. On a surge device, normally the line and neutral conductors are connected to the ground via a MOV. Think of the MOV as a pressure relief device, or in this case voltage. If it goes too high, its drained off to the ground. So in a way, anything hooked to this circuit after this device will be protected to some degree. Its always good to install surge protection at each point of use and at the entrance panel of your electrical system.