This Bundle has THREE items: the Reef Octopus OCTO Classic 110INT Protein Skimmer Bundle; a FREE MarineAndReef Reefractometer; & a Towel. For aquariums up to: 130 gallons, light bio load; 90 gallons, medium bio load; and 60 gallons, heavy bio load. The Reef Octopus OCTO Classic 110INT 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 130 gallons where sump space may be limited. Body Size: 5in. Footprint: 10.4in x 7in. Neck Size: 2.5in. Total Height: 19.75in. Output Size: 40mm/1.25in PVC. Output Height: 6.5in. Recommended Sump Water Height: 7 - 8in. Reef Octopus Aquatrance 1000s Pinwheel Pump: 92GPH & 9W. Features: Enhanced Performance Venturi Air Injection System, Reef Octopus Aquatrance 1000s Skimmer Pump, Refined Hybrid (half cone) Skimmer Body, Easy to Remove/Quick Release Collection Cup with Drain, Precision Water Level Control Output Valve, Air Intake Silencer, Solid Acrylic Construction, and Quiet and Energy Efficient Operation. The MarineAndReef Reefractometer is designed specifically for marine and aquarium salt water. The readout is for 0-40 PPT, which is much easier to read than the 1-100 PPT that comes with many refractometers that are for general use. The refractometer also features ATC (automated temperature compensation) so you don't need to adjust your reading. The MarineAndReef Aquarium Cleaning Towel is a durable, lint-free microfiber towel. 19" X 15". This Bundle has THREE items: the Reef Octopus OCTO Classic 110INT Protein Skimmer Bundle; a FREE MarineAndReef Reefractometer; & a Towel. For aquariums up to: 130 gallons, light bio load; 90 gallons, medium bio load; and 60 gallons, heavy bio load.