Penn-Plax Diving Sea-Dog (colors may vary) AIR DRIVEN ORNAMENTS BRING ANIMATION TO YOUR TANK: the real motion air driven ornaments movements provide fun and entertaining action while aerating your tank. DOG DIVES WITH A STEADY STREAM OF BUBBLES: the dog bobs up and down in your tank with the bubbles. PROVIDES MUCH NEEDED AERATION FOR YOUR TANK: bubbles escape the diving sea dog to provide your tank with much needed air. Requires air pump and standard 3/16 tubing (not included). MADE OF FISH SAFE AND DURABLE MATERIAL: the Penn Plax Aerating Diving Sea Dog is made from a durable plastic resin that is safe for your freshwater and saltwater / marine tank. SHOP PENN PLAX FOR ALL YOUR PETS NEEDS: continue to customize your aquarium with Penn Plax Action Ornaments and other decorations and dcor.