Up to 16 weeks (Each cube lasts up to 4 weeks). Cleans & freshens. Non-stop clean. Freshens. Safe for toilet components. Blue water. Sapphire waters. Helps fight toilet ring, hard water & limescale stains. Safe for toilet components. Easy to use. Septic tank safe. Please recycle. Questions or comments? Call 1-800-290-0158 or visit us at www.softscrub.com. Made in Poland.