I bought an extra set of filters when I bought my Cougar vacuum (reviewed elsewhere). Since I don't have a local supplier, I don't want to be left without a vacuum cleaner for a week if the filter fails. So far the original filters have not shown any wear after three months of use three to four days a week and there is absolutely no dust or ash coming out of the vacuum cleaner, so I'll take the chance and give it five stars. I will update later if the score is undeserved. Update 4th July 2014. Still using the original filters after almost 3 years with 8 months of winter. I've found that the extra fine ash migrates through the outer filter to the inner filter, so when suction drops, be sure to clean it with warm, soapy water. The foam filters under the outer top cover are also easily accessible by loosening the Phillips screws and removing the cover. However, this is not necessary unless you neglect the main filters for too long. These are really high quality filters!
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