Kem-Tek Power 99 3" Tablets are an advanced formula system designed to sanitize and suppresses algae and bacteria. Each jumbo 8 oz. tablet contains 99-percent Active Ingredient (Trichlor-S-Triazinetrione) and is conveniently sized to fit in floaters, skimmers and feeders. The tablets are slow-dissolving for long lasting sanitization. They contain a built-in stabilizer to protect from sunlight burn-off. Each tablet is individually wrapped.