Multi-Shock treatment dissolves rapidly and completely. Delivers 56% available chlorine. Convenient and easy to use. Ideal for shocking or super chlorinating pool water to destroy organic contaminants and restore crystal clarity to pool water. Buffered to 6.5 pH. Provides excellent balance when used with trichlor tabs, refer to Model No. F008025025PC (SKU 800402). Safe for all pool surfaces when used properly. Will not calcify sand filters. Active Ingredient: 99% Sodium Dichloroisocyanurate Dihydrate.