a spring for urging the second end portions of the pair of {HEAD ~ hair retainers} in {TAIL ~ a closing direction} thereof, 
a spring for urging the second end portions of the pair of { HEAD ~ hair retainers } in { TAIL ~ a closing direction } thereof ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH