Features: Drift-free Anchor Bubblers create a beautiful curtain of bubble that stays put. Clever plastic anchoring feet secures Anchor Bubbler in aquarium gravel to prevent drifting - will not float. Conventional suction-cup-mounted bubble wands can be only attached to aquarium wall surfaces. Allows versatile placement in your aquarium for discreet and creative displays of oxygenating bubbles. Airstones, curtains, and diffusers require an air pump and airline tubing for use.