Benzene,diethenyl-,polymerwithethenylbenzeneandethenylethylbenzene,sulfonated;Ethylbenzene,ethylethenylbenzene,diethenylbenzenepolymer,sulfonated;DOWEX-50W-HYDROGEN;DOWEX 50 W X 4;DOWEX 50 W X 4-CATION EXCHANGER, STRONGLY ACIDIC;DOWEX(R) 50 WX4;DOWEX(R) 50WX4-200;DOWEX(R) 50WX4-400