Reef Octopus Classic 150INT Protein Skimmer is a high-end skimmer that fits into constrained sump spaces. A member of the Reef Octopus Classic Series family, this compact skimmer provides efficient filtration for aquariums up to 150 gallons where sump space may be limited. As with every Reef Octopus protein skimmer, the Classic 150NT is constructed of high-quality cast acrylic and features an easy to adjust gate valve, a quick release neck for easy cup removal, cup drain, bubble diffuser, air shredding Aquatrance pinwheel pump and air silencer.