This warning sign is an ornament from Aqua Della's Army series. These themed ornaments are designed to coordinate with each other to create a cohesive look. It is made of polyester resin. This ornament is completely harmless and has no impact on the biological balance of your aquarium. The decoration is suitable for both freshwater and saltwater aquariums. Care instructions: Carefully remove the decoration from the box and rinse it with lukewarm water. Caution: Do not use soap, all-purpose cleaners, or other cleaning products (e.g., hydrogen peroxide, thinner, turpentine).