A+2000 Washable Electrostatic Permanent Custom Air Filter - 18" x 21" x 1" Quantity:Default and the greater the pressure

and the greater the pressure drop it creates

28X Increased Efficiency

Finally they are factory made so you don‰۪t have to deal with the hassle of trying to cut and size your custom air filters and they come with a full warranty

One way to overcome this problem is to increase the surface area of the filter media

degrade and restrict air flow

A+2000 Washable Electrostatic Permanent Custom Air Filter - 18" x 21" x 1" Quantity:Default and the greater the pressureYou may know them as washable air or even permanent air filters; some just refer to them as electrostatic filters. Either way, the "A+2000" brand Permanent Washable Electrostatic custom air filters are truly quality products, built to last a lifetime. Unlike some permanent custom air filters, the A+2000 uses no foam that may clog, degrade and restrict air flow, so it can provide a lifetime of dependable service. And there are no metal parts that could