A piston valve and {TAIL ~ a piston} are fastened into an inner compression chamber inside {HEAD ~ the compression cylinder} 
A piston valve and { TAIL ~ a piston } are fastened into an inner compression chamber inside { HEAD ~ the compression cylinder }
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD