The Welch Vacuum 2019B-01 one-head diaphragm vacuum pump has a 37 liter per minute (LPM) free air displacement with vacuum to 150 Torr and pressure to 18 pounds per square inch (psi). The portable utility vacuum/pressure pump is suitable for use in applications such as aspiration and vacuum filtration in non-corrosive environments. It accepts 115V, 60Hz input power and connects to 1/4" inside diameter vacuum system tubing (sold separately).Welch-Ilmvac, a subdivision of Denver Gardner, manufactures vacuum pumps, systems, and components for industrial and research applications under the Welch and Ilmvac brand names. Denver Gardner, founded in 1859, is headquartered in Milwaukee, WI.