Are replacement filters as good as genuine OEM filters?

It depends on the filter, and the listing tells you. Some of our replacements match what the OEM lists for its own part: Amtech lists the 351D66A2387 as a fire-retardant nanofiber cartridge with 254 sq ft of media, the same as our replacement. Others differ in media, media area or frame, and the listing says how. Compare the specifications on the two listings before you choose.

Do you sell genuine OEM filters?

Yes: genuine Airflow Systems, FumeVac, IVEC and Dustcontrol filters, and their listings start with "Genuine". For other brands we carry non-OEM replacements, and each listing names the OEM part numbers it replaces.

Why is a filter listed as an alternative instead of a replacement?

Because it shares the OEM part's size but differs in a way that matters. Our non-fire-retardant nanofiber oval cartridge is the same size as the Donaldson Torit P191889, but the P191889 is fire-retardant, so the non-FR cartridge is listed as an alternative and the fire-retardant one as the replacement.

Can I return a filter I don't need?

Yes, within 30 days and with no restocking fee, if it is unused, in the condition you received it and in its original packaging. Returns are arranged with us first, and on returns that aren't a fit problem the customer pays return shipping.

Genuine OEM vs Replacement Filters

What separates a genuine OEM filter from a non-OEM replacement, what to compare on the two listings, and how the fit guarantee covers a replacement.Updated November 14, 2026

Genuine, replacement or alternative

Each listing on Rx4CleanAir says what kind of filter it is:

Genuine (OEM): the equipment maker's own part. We carry genuine Airflow Systems, FumeVac, IVEC and Dustcontrol filters, and their listings start with "Genuine".
Replacement: a non-OEM filter listed as the replacement for one or more OEM part numbers. The listing names every OEM number it replaces, and our fit guarantee covers it.
Alternative: a few filters share an OEM part's size but differ in a way that matters, so they are listed as an alternative rather than a direct replacement. 50551 is the same oval size as the Donaldson Torit P191889, but its nanofiber media is not fire-retardant; the fire-retardant replacement for the P191889 is 50552.

What stays the same, and what can differ

A replacement matches the part it replaces in size and fit. Our replacement for the Airflow Systems 7FB9-0132 bag, for example, has the 7FB9-0132's 24 x 24 x 32 in. size, 95% efficiency and 10-pocket design with loops. What can differ is stated on the listing:

Media. The genuine Airflow Systems 7FR0-2016 cartridge uses CLEAN-2 media; our replacements for it use UltraLife (MERV 15) or 80/20 (MERV 11).
Media area. The genuine 7FB9-0132 bag has 120 sq ft of media and our replacement has 106 sq ft. The other way round, the Camfil Farr 325325-002 cartridge has about 325 sq ft of media and our replacement has 350 sq ft.
Frame. The genuine Airflow Systems 7FP9-5401 box filter has a cardboard frame; our replacement has a metal frame.
Fire-retardant media. Each listing states whether its media is fire-retardant. If your filters were fire-retardant, stay with fire-retardant.

Genuine and replacement side by side

Where we stock both, the replacement's listing names the genuine part.

OEM part	Genuine	Replacement	The same	Different
Airflow Systems 7FB9-0132 bag	50505	50456	24 x 24 x 32 in., 95% (MERV 15), 10 pockets with loops	Media area: 120 sq ft genuine, 106 sq ft replacement
Airflow Systems 7FB9-0126 bag	50504	50455	24 x 24 x 26 in., 95% (MERV 15), 10 pockets with loops	Media area: 88 sq ft genuine, 87 sq ft replacement
Airflow Systems 7FP9-5401 box	51032	50966	10 x 20 x 6 in., 95% (MERV 14)	Frame: cardboard genuine, metal replacement

Our replacements against the OEM's own specifications

For these parts we stock the replacement only. The middle column is what the OEM lists for its own part, as quoted on our listing.

OEM part	What the OEM lists	Our replacement
Amtech 351D66A2387	Fire-retardant nanofiber, 254 sq ft	50548: fire-retardant nanofiber, MERV 15, 254 sq ft
Amtech 351D91A3287	Fire-retardant nanofiber, 350 sq ft	50581: fire-retardant nanofiber, MERV 15, 350 sq ft
Amtech 351D66A1196 / 351D66A8596	Spunbond polyester, 125 / 100 sq ft	50550: fire-retardant spunbond polyester, MERV 11, 120 sq ft
Trion 248300-002	Fire-retardant cellulose, 226 sq ft	50590: fire-retardant 80/20, MERV 11, 226 sq ft
Camfil Farr 325325-002	About 325 sq ft of fire-retardant blended media	50628: fire-retardant nanofiber, MERV 15, 350 sq ft
Airflow Systems 7FR0-2020	CLEAN-2, 150 sq ft	50698: UltraLife, fire-retardant, MERV 15, 140 sq ft; 50542: 80/20, fire-retardant, MERV 11, 140 sq ft
Airflow Systems 7FR0-2016	CLEAN-2, 150 sq ft	50697: UltraLife, fire-retardant, MERV 15, 140 sq ft; 50541: 80/20, fire-retardant, MERV 11, 140 sq ft

How to choose

Start with the part number on the old filter's label or end cap. Search it at the top of the page or look it up in the filter cross reference; the results show the genuine part, our replacement, or both.
Compare the two listings when both exist: media, MERV or efficiency, media area, frame and fire-retardant media are all on each listing.
Keep fire-retardant media if the filters you are replacing were fire-retardant.
Not sure? Send the make and model of your collector through the chat button or a quote request, and we confirm the match before you order.

Fit guarantee and returns

If you order the filter we list as the replacement for the OEM part number on your equipment and it doesn't fit, we replace it or refund it, and we pay the return shipping. Other returns are accepted within 30 days with no restocking fee, when the item is unused, in the condition you received it and in its original packaging, and the return is arranged with us first; on those, the customer pays return shipping. The full terms are on the return policy page.

Amtech, Trion, Camfil Farr and Donaldson Torit are trademarks of their respective owners and are used here for cross-reference only; Rx4CleanAir is not affiliated with them.

Frequently asked questions

Are replacement filters as good as genuine OEM filters?: It depends on the filter, and the listing tells you. Some of our replacements match what the OEM lists for its own part: Amtech lists the 351D66A2387 as a fire-retardant nanofiber cartridge with 254 sq ft of media, the same as our replacement. Others differ in media, media area or frame, and the listing says how. Compare the specifications on the two listings before you choose.
Do you sell genuine OEM filters?: Yes: genuine Airflow Systems, FumeVac, IVEC and Dustcontrol filters, and their listings start with "Genuine". For other brands we carry non-OEM replacements, and each listing names the OEM part numbers it replaces.
What if a replacement filter doesn't fit?: If you order the filter we list as the replacement for the OEM part number on your equipment and it doesn't fit, we replace it or refund it, and we pay the return shipping. If you're not sure which part your unit takes, send us the make and model and we confirm before you order.
Why is a filter listed as an alternative instead of a replacement?: Because it shares the OEM part's size but differs in a way that matters. Our non-fire-retardant nanofiber oval cartridge is the same size as the Donaldson Torit P191889, but the P191889 is fire-retardant, so the non-FR cartridge is listed as an alternative and the fire-retardant one as the replacement.
Can I return a filter I don't need?: Yes, within 30 days and with no restocking fee, if it is unused, in the condition you received it and in its original packaging. Returns are arranged with us first, and on returns that aren't a fit problem the customer pays return shipping.