{TAIL ~ A window unit frame} is received in each clear window opening supported by and electrically connected to {HEAD ~ the frame} 
{ TAIL ~ A window unit frame } is received in each clear window opening supported by and electrically connected to { HEAD ~ the frame }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD