At least one glow rod has {TAIL ~ a contact part} that is spring mounted at the glow rod in {HEAD ~ an axially displaceable fashion} 
At least one glow rod has { TAIL ~ a contact part } that is spring mounted at the glow rod in { HEAD ~ an axially displaceable fashion }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD