{HEAD ~ Axially spaced apertures} in {TAIL ~ the housing} support a manually controlled shaft for rotation 
in
{ HEAD ~ Axially spaced apertures } in { TAIL ~ the housing } support a manually controlled shaft for rotation
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH