{TAIL ~ The housing} 20 is generally rectangular in shape, but may have {HEAD ~ any suitable shape} 
{ TAIL ~ The housing } 20 is generally rectangular in shape , but may have { HEAD ~ any suitable shape }
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD