{TAIL ~ A hollow compensating spool} is slidably arranged within the hollow cage between {HEAD ~ the cross sectional holes} 
{ TAIL ~ A hollow compensating spool } is slidably arranged within the hollow cage between { HEAD ~ the cross sectional holes }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD