The MARINA Algae Magnet enables you to clean the inside of the aquarium's glass without getting your hands wet. The powerful magnets ensure a tight grip and the non-abrasive cleaning pads will not scratch the glass surface. Suitable for fresh and saltwater aquariums. - Medium - Allows cleaning of inside glass without using hands in the water - Powerful magnet on the outside - Safe for fresh or salt water - Non-abrasive cleaning pad will not scratch