{TAIL ~ A typical E glass composition} is about 53.5% by weight silicon dioxide , about 8% boron oxide , {HEAD ~ about 14.5% aluminum oxide} , about 21.7% calcium oxide , and about 1.1% magnesium oxide  
{ TAIL ~ A typical E glass composition } is about 53.5 % by weight silicon dioxide , about 8 % boron oxide , { HEAD ~ about 14.5 % aluminum oxide } , about 21.7 % calcium oxide , and about 1.1 % magnesium oxide
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH