The Holmes ROHAPF41M is the correct replacement pre-filters for the following air purifiers:
The Holmes HAPF41 Air Purifier Carbon PreFilter-2 Pack is a replacement pack of carbon pre-filters for the Holmes HAP-300 and Holmes HAP-3004 air purifiers. This 2 pack of carbon filters protects the HEPA filter of your Holmes air cleaner and prevents the HEPA filter getting clogged by larger particles. With these Holmes pre-filters you will be able to increase the life of your HEPA filter and Holmes air cleaner. Holmes recommends you replace these air filters every 3 to 6 months to achieve the best performance.
Holmes HAPF41 Air Purifier Carbon PreFilter-24 Pack specifications:
The Holmes carbon pre-filter traps larger particles and eliminates or reduces odors from smoking, cooking. This filer also traps particles such as pet hair, dust, and lint.