{TAIL ~ said sleeve} is formed with entrances to {HEAD ~ said at least one shaft} at opposite narrow ends of said sleeve, 
{ TAIL ~ said sleeve } is formed with entrances to { HEAD ~ said at least one shaft } at opposite narrow ends of said sleeve ,
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH