The profiles are initially provided in {HEAD ~ the fully engaged condition} within {TAIL ~ an elongate, longitudinally cut tube} 
within
The profiles are initially provided in { HEAD ~ the fully engaged condition } within { TAIL ~ an elongate , longitudinally cut tube }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL