Iron Out Automatic Toilet Bowl Cleaner features a new long-lasting advanced concentrated formula designed to repel rust and iron stains in both toilet tanks and bowls. This easy-to-use cleaner works with every flush, providing continuous cleaning without the need for scrubbing. Simply drop a tablet in the tank and forget about it, as it rinses away rust stains while keeping your toilet tank and bowl stain-. Each tablet lasts up to 30 days, and the box contains 2 tablets. The formula is safe for plumbing and septic tanks and contains no phosphates. For results, do not mix with bleach or other household cleaners, and avoid using it with other in-tank cleaners. Model Number: AT12T