Our toilet cleaner is carefully formulated with sodium bicarbonate and sodium dodecyl sulfate. Designed specifically for cleaning the interior of the toilet while flushing. The usage method is extremely convenient: This product contains three cleaning blocks. Just put in one each time. Put the cleaning blocks into the dedicated container (it is recommended to use the original container). Change to the next one after using one. Put the container with the cleaning block into the toilet tank and let it sink naturally. Let it stand for about 10 minutes until the cleaning block is completely dissolved and you can start working. After each use of the toilet， flush it normally to complete the automatic cleaning. Each cleaning block can be used for approximately 2 to 3 days， which may vary depending on the amount of water and the frequency of use. And it can automatically clean the internal pipes of the toilet， reducing the residue of dirt.