Penn Plax Aerating Action Ornament, Barrel of Jewels - Opens and Closes - Small AIR DRIVEN ORNAMENTS BRING ANIMATION TO YOUR TANK: the real motion air driven ornaments movements provide fun and entertaining action while aerating your tank. BARREL OPENS AND CLOSES WITH THE STEADY STREAM OF BUBBLES: the barrels cover rises and falls with the bubbles to reveal the treasure inside. PROVIDES MUCH NEEDED AERATION FOR YOUR TANK: bubbles escape the barrel of jewels 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 Barrel of Jewel 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.