The Classic 90 skimmer is a totally new hang on skimmer, not like your common hang on design, it have a cylindrical main body and uses siphon to feed water in to the skimmer which reduces the load on the pump while increasing the air generated. Capable of skimming the top of the water surface avoiding the ugly oil buildup that can accumulate and hinder light penetration. A cylindrical reaction chamber, the bubble chamber and conical body to neck transition,all help disperse the air gently and reducing turbulence as the collected organics make it into the collection cup. It is also very easy to be set up. Two adjustable PVC screws makes it could be stably fixed on your aquarium tanks. Rated for aquariums up to 100 Gallons Footprint: 7.5" x 7.5" | Body Diameter: 4" | Height: 23.8" Powered by: Aquatrance 1000 Pinwheel Pump Feature - Cylindrical Body Design - Traditional Style Collection w/ Drain - Pump Mounted External to the Skimmer - Turbulence Reducing Bubble Plate - Easy to Remove Collection Cup - Air Silencer - Precision Control Output Valve - Solid Construction Filtration Handling - 100 gallon – Light Filtration Demand - 90 gallon – Medium Filtration Demand - 75 gallon – Heavy Filtration Demand Technical Specs - Body Size: 4" - Footprint: 7.5" x 7.5" - Total Height: 23.8" - Box Size: 18" x 18" x 12" Aquatrance 1000s Pinwheel Pump - Wattage: 9w - Air Draw: 420 lph / 15 SCFH* - Water Draw: 350 lph / 92 GPH* *Air and water results will vary depending on aquarium setup Warranty -2 Manufacturer’s year warranty on pump and 1 year on skimmer body