A trouble free biological filter designed with adjustable 1 dia. uplift tubes for better water circulation and multiple-plate construction for easy installation. Includes airline tubing and discard-A-Stone and features the fish-saver cleaning elbow. Advanced design allows a separate plate installation and also has optional flow-thru set-up for use with a power head. Made of special quality plastic which resists splitting and cracking. Available in three different styles to fit rectangular hexagonal octagonal and flatback aquariums. Available in three different sytles to fit rectangular hexagonal octagonal and flatback aquariums. Packaging Boxed.