A voltage surge suppressor 1 further comprising {TAIL ~ diagnostic means} to indicate the status of {HEAD ~ the varistor} 
A voltage surge suppressor 1 further comprising { TAIL ~ diagnostic means } to indicate the status of { HEAD ~ the varistor }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD