The treasure chest has an airline to connect to an air pump line but it needs an air pump that can be adjusted down to very few eminating bubbles or the treasure chest lid will remain fully open.
And when be set up, a vivid treasure seeking will appear in your fish tank. It would be very nice and add more fun for your little baby fish.

The treasure chest will be lighter than water when poured with oxygen, so you need to use 1 or 2 suction cup to fix it in an aquarium without gravel.
For a tank with sand or gravel, just put some sand or gravel in or around the chest and it's done.
Then a vivid and interesting scene will be created in your tank.

What makes the product worth to buy is not its size or weight but its creative design, run by an air pump to imimate a diver who is searching for treasure.
Please mind the measurement in the fifth image. The item may be not as large as you think.

How to make it work:
1. Connect the pump interface to an air pump or an adjustable air valve.
2. Put the chest in your aquarium and set the position.
3. Adjust the air pressure to make the chest diver active according to your needs.

Package includes:
1* treasure diver

The Tagline of Bestgoo Tank Ornament is 'Entertain Your Little Ones Then to Please You...We Know It's Really for You! '
Winter is coming. It looks bleak everywhere. Purchase a gift for you and your lovely fish to add a beautiful view in your tank. Human need something fun to delight themselves, pet also!

• Made from premium resin and plastic, durable, non-toxic and pollution-free. Absolutely safe for the fish you beloved.
• Real motion air-driven ornaments provide entertaining action while aerating your tank. Great-looking ornament and really fun to watch when set up.
• When the diver floats the treasure chest will open and closes to revealing the treasure inside, more vivid and active
• Ideal for various fish tank and safe for fresh and salt water, either your freshwater fish or saltwater fish can play with their new toy.
• Requires an air pump (Not Included) & 3/16" tubing (Not Included) and an air valve to control the flow of the air to the chest, then you can adjust the frequency in which the lid opens.

Made from premium resin and plastic, durable, non-toxic and pollution-free. Absolutely safe for the fish you beloved.Bestgoo