{HEAD ~ A second fabric}, which may also be permeable and defines {TAIL ~ a second moving conveyor}, is also included 
{ HEAD ~ A second fabric } , which may also be permeable and defines { TAIL ~ a second moving conveyor } , is also included
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH