Balston vacuum pump exhaust filters remove oil mist and reduce noise from vacuum pumps. They are rated for flows from 3 to 850 cfm and remove heavy concentrations of fine oil droplets (below 2 ┬Ám) from vacuum pump exhaust. Filter cartridges continuously drain collected liquid back into vacuum pump. Parker Hannifin Corp., Filtration and Separation Div., (800) 343-4048, www.parker.com/balston