Look for the product label on the rear or underside of the purifier. Keep the full model code and take a photograph so letters and suffixes do not get lost.
For the first Levoit record, the manufacturer lists Core 300-P and Core 300S-P. Search the complete code rather than just “Core”. A Core 400S or Core Mini needs a different reference check.
For Coway, read the AP code as well as the Airmega name. Our initial set is listed for Mighty AP-1512HH and 200M AP-1518R. “Mighty” by itself is not a code for every Mighty generation.
For Blueair, retain every part of Blue Pure 211i Max. The 211+ and 211+ Auto names do not identify the same filter as F2MAX.
You can search with a purifier model or a filter reference such as F2MAX. Open the result and compare its listed models with your label before using the buying link.