- Keep trapping large particles in air and filter off such as dust, fibers, lints, puff, smoke. 
- Keep your house (living environment) in fresh and clean all year round, block the odors and particles which cause odors, allergy and hay fever. Leave your living environment is a dust free status. - The product comes with a flexible size which can be cut to a appropriate size to suit your own purifier model. It also comes with a reserve velcro tape which can be used to other Honeywell models if the model pre-filter has a size of less than 119cm x 25.2 cm. 
- It is highly recommended to replace the pre-filter in every 3 months. The best period of performance depends entirely on the room air condition. The more pollute of the environment, the shorter of the performance life. 
- Correct using the pre-filter can optimize your Hepa Filter Life. No need to cut the pre-filter as it fits perfectly for Honeywell Model 50250-S.