Series 660/680 WOB-L® Piston pumps from Thomas incorporate a package of features to provide cleanair-flow, long life, excellent efficiency, low noise and low vibration. These pumps are well-suited to avariety of medical and environmental applications, including oxygen concentrators, blood analyzers,dental carts and ozone generators.The pumps' oil-less pistons and cylinders, plus efficientintake filters, ensure a non-contaminated air flow.Stainless steel valves, high-performance piston seals,hard-coated aluminum cylinders and permanentlylubricated bearings offer long-life performance. Wettedaluminum parts are treated for corrosion protection.The pumps' single-phase AC motors are of ultrareliablepermanent split capacitor design, which eliminates theneed for a starting switch.Series 660/680 pumps provide up to 28.5 in. Hg (-965 mbar) of vacuum, or 45 psi (3.1 bar) of pressure.Maximum flow is rated at 2.37 CFM (67.1 LPM).