Eshopps' PSK-100H protein skimmer combines a high performance Sicce SE-200 needle wheel pump with the simplicity of a hang-on model. Features a removable collection cup for easy removal of waste and a bubble plate to concentrate and direct the flow of air bubbles for increased performance. Adjustable knob allows for easy fine tuning of water level to meet the needs of your ecosystem. Durable acrylic construction designed to last. Great for saltwater and reef aquariums up to 100 gallons; the skimmer measures 7 in. x 7 in. x 23 in. For more information; please read What is a Protein Skimmer? from our article archive.