A cover is disposed over the membrane and is sealingly engaged with the body to accommodate {HEAD ~ axial sliding movement} from an outer position to {TAIL ~ an inwardly displaced position} 
to
A cover is disposed over the membrane and is sealingly engaged with the body to accommodate { HEAD ~ axial sliding movement } from an outer position to { TAIL ~ an inwardly displaced position }
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 OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL