The 4 lb More Chlorine 65 is a powerful pool shock treatment designed to maintain clean, clear, and safe pool water. With a 65% concentration of calcium hypochlorite, this product is highly effective in sanitizing your pool or spa by eliminating bacteria, algae, and other contaminants. Available in granule or crystalline form, it is easy to apply and provides fast-acting results to quickly restore water clarity and hygiene. The 4 lb pail offers convenience and ease of use for regular pool maintenance.