{TAIL ~ a single, removable plate} that is detachably mounted on the yoke in a selected one of first and second positions by invertibly repositioning said {HEAD ~ removable plate} 
{ TAIL ~ a single , removable plate } that is detachably mounted on the yoke in a selected one of first and second positions by invertibly repositioning said { HEAD ~ removable plate }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD