Package of two commercial grade 203370 prefilters for F50F or F300 series. We measured the size at 10 x 20 x 5/16. Two of these prefilters are used in the Honeywell 20 x 20 air cleaners.
These prefilters are a genuine product of the Honeywell Commercial Air Products Division. The Commercial products have higher standards for design, assembly, procurement, and production.
Prefilter Upgrade Fits
Permatron polypropylene filters tests shows 43% increase in average arrestance efficiency over metal mesh prefilter. See Poly-203370
the F300E1027, F300A2020 and F50F1032 air cleaner.
This 203370 prefilter is for the F300E F300A F50F Series and will NOT fit
the the F50A or F50E Series. Read below for more info.