The Rheem Standard Pleated filter is made of a wire-backed pleated media. This filter provides up to 90 days of protection against many airborne particles that can aggravate seasonal allergies and cause unhealthy environments. The Rheem Standard Pleat is convenient and easy to replace which makes it a great choice for improving indoor air quality. The Rheem Standard Pleat is effective against the following contaminants: pollen, pet dander, nuisance dust, and dust mite debris. Filters come in a handy 3-pack so you're set for a season. The leader in the air filtration, Flanders provides air filtration products for pharmaceutical laboratories, the space programs, nuclear containment, and commercial industries.