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