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