Air travels through said tube and passes through {HEAD ~ a plurality} of {TAIL ~ holes} along the length of the tube in the general direction of the area where the laser beam strikes the workpiece 
of
Air travels through said tube and passes through { HEAD ~ a plurality } of { TAIL ~ holes } along the length of the tube in the general direction of the area where the laser beam strikes the workpiece
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL 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