Mer-Maid automatic toilet bowl cleaner is the easy solution to keeping your toilet clean. It works hard so you don't have to. If the water is blue, Mer-Maid is working for you. Cleans and freshens your toilet bowl. It's so easy. Just drop it in your tank and Mer-Maid will clean your toilet with every flush for up to 3 months. Sustained-release technology releases the right amount of ultra-strength cleaning solution. Helps break down tough stains and residue on your toilet bowl that nasty build-up is a chore to scrub with a brush.