An outer nut 28 is threadably engageable with the distal male threaded portion outwardly of the second hub collar 23 such that tightening or loosening the nut respectively moves the hub collars toward or away from each other to bring {HEAD ~ the cap rims} into and out of {TAIL ~ sealing engagement} with their respective tire openings 
out of
An outer nut 28 is threadably engageable with the distal male threaded portion outwardly of the second hub collar 23 such that tightening or loosening the nut respectively moves the hub collars toward or away from each other to bring { HEAD ~ the cap rims } into and out of { TAIL ~ sealing engagement } with their respective tire openings
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH