Meguiar s M47 Marine/RV Hard Water Spot Remover M4716 16oz. is formulated to chemically break down and remove hard-water minerals from your vehicle s surface. The thick low-drip formula clings to vertical surfaces for easy cleaning eliminating the need for extensive wiping and buffing. Our formula safely and quickly removes tough hard-water spots while protecting against new spots. The convenient spray bottle makes it even easier to apply and use. If surface has been etched from previous hard-water deposits and more cleaning is needed use Meguiar s M67 Marine/RV One Step Compound or M49 Marine/RV Oxidation Remover.