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