Rather, the closure is such that the free exchange of gas between {HEAD ~ the internal volume} of {TAIL ~ the capped swab transport tube assembly} and the external environment is allowed 
Rather , the closure is such that the free exchange of gas between { HEAD ~ the internal volume } of { TAIL ~ the capped swab transport tube assembly } and the external environment is allowed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH