{HEAD ~ The gauge} also has {TAIL ~ a pair} of rest bars mounted on the base plate to support the brake block at the specified radius at first and second measuring points 
has
{ HEAD ~ The gauge } also has { TAIL ~ a pair } of rest bars mounted on the base plate to support the brake block at the specified radius at first and second measuring points
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL 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 OTH OTH OTH