The toilet tank bank is designed to be filled with fresh water and inserted into your toilet cistern using the clip. This means that when the toilet is flushed the cistern never empties fully, saving water as less water travels back into the cistern after flushing. Ideal for older style cisterns with flush levels between 9 and 12 litres. Made from non-corrosive materials that resist microbes and fungal growth. One toilet tank bank can take up to 2 litres of water and features an airlock fill valve to prevent evaporation, meaning the bag never needs refilling. It is a maintenance-free product and includes a clip for secure placement within the cistern, preventing it from floating or interfering with toilet mechanisms.