This replacement part consists of a pair of synthetic filters mounted on a metal frame, except for the 500 and 1000 models that have only one filter. The replacement part lasts more than 3000 hours when used correctly. The Clogged Filter Detection Device installed on the electric panel of the mist collector flashes to warn the user that the filter is only 15% efficient, allowing plenty of time to order a replacement. Replace this part by opening the Pre-Filter access door and removing the filters from the rails. The replacement is installed by following the procedure in the reverse order.