{HEAD ~ The grid} is composed of glass containing lead oxide, and eliminates {TAIL ~ the spacer material} used in prior known grids, and is therefore, an air core grid 
eliminates
{ HEAD ~ The grid } is composed of glass containing lead oxide , and eliminates { TAIL ~ the spacer material } used in prior known grids , and is therefore , an air core grid
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH