A press is mounted to {TAIL ~ the base} to selectively press {HEAD ~ the press block} against the gasket and hold it in position 
A press is mounted to { TAIL ~ the base } to selectively press { HEAD ~ the press block } against the gasket and hold it in position
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH