Penn Plax 3-Inch Bubble Disk Air Pump Accessories Provides a continuous tower of bubbles to help aerate your aquarium Durable plastic can be buried or hidden to add to your dcor Uses a standard 3/16" tubing connection Provides a continuous tower of bubbles to help aerate your aquarium Durable plastic can be buried or hidden to add to your dcor Uses a standard 3/16" tubing connection Provides a continuous tower of bubbles to help aerate your aquarium Durable plastic can be buried or hidden to add to your dcor