The Welch 2014B-01 DryFast Chemical Duty Diaphragm Pump provides tune able control, precisely within 1 Torr. An excellent vacuum pump for the most harsh chemical processes. The Welch 2014B-01 is lightweight, with a control knob ergonomically easy to use, front and center of the pump. At 35 Torr, the 2014B-01 is the perfect filtration, aspiration or general lab vacuum use pump for harsh vapors.