At AquaCave, we offer some of the best selection & best prices on Sweetwater linear air pumps for you marine, reef, and freshwater aquarium. Sweetwater linear air pumps are not linear diaphragm air pump s but true linear piston type air pump s. Since the only moving part - the piston - floats on a bed of air, an exceptionally long service life can be expected (8 years of continuous life is not uncommon). With Sweetwater linear air pumps you'll get quiet, energy-efficient operation and clean, oil-free air. Sweetwater linear air pump has an outdoor-rated housing, grounded power cord, 1/2" MNPT flex outlet and 115V/60 Hz are all standard. UL-listed. Sweetwater linear air pumps are covered with 3-year manufacturer's warranty.