Automatic toilet bowl cleaner offers a quick, hassle-free way to keep your toilet cleaner than ever. Its easy-to-use design requires you to simply place a single puck into the back of your toilet tank to help keep your bowl stain-free. Then with every flush, it cleans and deodorizes your toilet bowl and repels tough hard water, mineral and lime scale stains. Mild formula ensures that the bowl water is not harmful to children or pets, and won't harm plumbing or septic systems.