A pair of {HEAD ~ blowers} 83, 83, blow {TAIL ~ cooling air} over heat sinks 82, 82 
A pair of { HEAD ~ blowers } 83 , 83 , blow { TAIL ~ cooling air } over heat sinks 82 , 82
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH