Penn-Plax Bubble-Wall Air Diffusers for Aquariums produce a spectacular wall of bubbles in any aquarium. These diffusers create a dramatic mist of healthful bubbles along the entire length. Simply connect your air pump (not included) and the Bubble-Wall will evenly distribute fine bubbles through a super-porous, non-clogging wand. The tough polycyl material stands up to continual use. Additional Bubble-Wall diffusers can be joined using the enclosed connector to create almost any length and each can be cut with a razor blade to divide or shorten.