Marina White Airstone 3 pack

these fit all standard air hose tubing (4mm inside diameter)

The Marina air diffuser is ideal for adding bubbly highlights in your aquarium. Simply connect the air diffuser to your airline tubing and place it in desired location.

Weigh it down or simply cover it with gravel.

3-pack. 

This will also fit all Biorb Aquariums just simply pull off the red end and insert.