Carbon Activated Pre-Filter 4-pack for use with the GermGuardian FLT5250PT True Hepa Filter with Pet Pure Treatment Filter C Pet 4-Pack of Carbon Activated Pre-Filters Made in the USA from BulkFilter Brand Material These PreFilters are designed to fit the FLT5250PT True Hepa Filter with Pet Pure Treatment Filter C Pet Carbon Activated filters extend the life of the hepa filter and remove common household odors Each filter is 4.8"x19.25" and is desinged to be a direct replacement for existing Pre-Filter MADE IN THE USA