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