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 watch when set up. Real underwater movement directions: the air pipe with decorations on the setting valve or pump connections. Put in the aquarium decorations and fixed position. Adjust the air pressure to make decorations to get your ideal movement effects. Requires an air pump (not included) and 3/16" tubing (not included). then you can adjust how often the lid opens. attached to the chest suspended in the water, with oxygen, divers in the water floating swing, such as the chest should strive to explore the way; When the diver floats the treasure chest will open and will snap shut to reveal the treasure inside, more vivid and active Ideal for various aquariums and safe for both fresh and salt water, your freshwater fish or saltwater fish can play with it their new toy Box dimensions: 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. Product Description The ornament of tank is "Maintain your little ones so to satisfy you... We know this is really for you Winter is coming. It looks dark everywhere. Buy a gift for you and your lovely fish to add a beautiful sight in your tank. Humans need something fun to treat themselves, pets too The treasure chest will be lighter than water when poured with oxygen, so you need to use 1 or 2 suction cups to fix it in an aquarium without gravel. For a tank with sand or gravel, just put sand or gravel in or around the chest and it's done. Then a scene lively and interesting will be created in your tank. What makes the product worth buying is not its size or weight, but its design, operated by an