Penn Plax Action Air ornaments bring animation, charm, and life to your underwater world while aerating your tank. The action of this barrel opening and closing reveals the interior treasure while bubbles escape to provide your tank with much needed air. Simply connect the ornament to a standard 3/16 airline from your air pump (not included) and watch as the steady stream of bubbles opens and closes the barrel of jewels. Use your pressure control valve (not included) to adjust the motion and volume of air, if desired.