The grooves engage corresponding annular ridges formed adjacent the top of the plunger when {HEAD ~ the plunger} is inserted in {TAIL ~ the syringe cylinder}, preventing withdrawal of the plunger from the cylinder 
The grooves engage corresponding annular ridges formed adjacent the top of the plunger when { HEAD ~ the plunger } is inserted in { TAIL ~ the syringe cylinder } , preventing withdrawal of the plunger from the cylinder
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH