Non-toxic and eco-friendly materialsMade from quality resin and plastic, durable, non-toxic and pollution-free, safe for your fish; Absolutely safe for the fish you love. Great-looking ornament and really fun to look at when put up. Actual underwater movement directions: the air pipe with decorations on the valve adjustment or pump connections. Put in the aquarium decorations and fixed position. Adjust the air pressure to make decorations to achieve your ideal motion effects. Requires an air pump (not included) and 3/16" tubing (not included). Then you can adjust the frequency in which the lid opens. Chest sink at the bottom, the plungers of the 'chains' attached to the chest suspended in the water, with oxygenation, divers in the water floating swing, as the chest should strive to explore the way; When the diver floats the treasure chest will open and close to reveal the treasure inside, more vivid and active Ideal for various aquariums and safe for fresh and salt water, your freshwater fish or saltwater fish can play with their new toy Dimensions of the box: 5.5cm x 4cm x 5cm/2.15'' x 1.56'' x 1.95'' (approx), Frogman size: 10cm x 6cm x 2cm/3.9'' x 2.34'' x 0.78'' (approx). please confirm the product size carefully before purchase.