The yarn is fed through {HEAD ~ a hole} in {TAIL ~ the wall} of the tube from a groove on the outer surface 
The yarn is fed through { HEAD ~ a hole } in { TAIL ~ the wall } of the tube from a groove on the outer surface
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH