{TAIL ~ A single hand apparatus} for opening and closing the cap of {HEAD ~ a microcentrifuge tube} 
{ TAIL ~ A single hand apparatus } for opening and closing the cap of { HEAD ~ a microcentrifuge tube }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD