The Fluval Q2 Air Pump is powerful yet extremely quiet. It produces constant air flow thanks to the advanced swing-arm & diaphragm design. The double walled construction, intergrated pump well & engineered noise suppressing baffle chamber make Fluval one of the quietest air pumps to date. The Q2 is quality constructed & will provide lasting & reliable performance for aquariums up to 600L (160 U.S. gal)