It is very important that the parts do not come apart after {TAIL ~ the training device} has been assembled for {HEAD ~ use} 
It is very important that the parts do not come apart after { TAIL ~ the training device } has been assembled for { HEAD ~ use }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD