The variation in {TAIL ~ stiffness} may provide stiffer projections at the gap in {HEAD ~ the split ring}, i.e. towards the ends of the strip of material that are curved towards each other to form the ring 
The variation in { TAIL ~ stiffness } may provide stiffer projections at the gap in { HEAD ~ the split ring } , i.e. towards the ends of the strip of material that are curved towards each other to form the ring
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH