Safe for Fish - Made from premium resin and plastic, durable, non-toxic and pollution-free. Absolutely safe for fish. Add Funny for Aquarium - When the diver floats the treasure chest will open and closes to revealing the treasure inside, more vivid and active. Safe for Fresh and Salt Water - Ideal for various fish tank and safe for fresh and salt water, either your freshwater fish or saltwater fish can play with their new thing. Unique design, vivid colors, realistic image, suitable for fish tank, aquarium. It is an important instrument to successfully keep aquatic fish for respiration process.Increase oxygen levels, lower CO2 and raise PH.